Exhibit 10.21

                              OFFICE BUILDING LEASE


1.     PARTIES This Lease,  dated, for reference purposes only, July 10, 1993 is
       made by and  between  The Joseph  and Eda Pell  Revocable  Trust  (herein
       called  "Landlord")  and Fair,  Isaac and Company,  Incorporated  (herein
       called "Tenant").

2.     PREMISES  Landlord  does hereby lease to Tenant and Tenant  hereby leases
       from  Landlord  that certain  office  space  (herein  called  "Premises")
       indicated on Exhibit "A"  attached  hereto and  reference  thereto made a
       part hereof,  said Premises being agreed, for the purposes of this Lease,
       to have an area of  approximately  35,261 rentable square feet and 33,140
       useable  square feet,  being situated in Suite 200 on the second floor of
       that certain Building known as Regency Center,  100 Smith Ranch Road, San
       Rafael, CA 94903.

       Said Lease is subject to the terms,  covenants and conditions  herein set
       forth and the Tenant  covenants as a material  part of the  consideration
       for this Lease to keep and perform each and all of said terms,  covenants
       and  conditions  and that this Lease is made upon the  condition  of said
       performance.

3.     TERM The term of this Lease shall be for seven (7) years,  commencing  on
       the 1st day of  December,  1994,  and ending on the 30th day of November,
       2001.

       See Addendum to Lease, P. 4, Commencement.

4.     POSSESSION See Addendum to Lease, P. 3, Possession.

5.     A.    RENT Tenant  agrees to pay to Landlord as rental for the  premises,
             without  prior notice or demand,  the sum of Seventy  Thousand Five
             Hundred Twenty-two Dollars  ($70,522.00) on or before the first day
             of the first full calendar  month of the term hereof and a like sum
             on or before  the first day of each and every  successive  calendar
             month  thereafter  during the term  hereof,  except  that the first
             month's rent shall be paid upon the  execution of this Lease.  Rent
             for any period during the term which is for less than one (1) month
             shall be a prorated  portion  of the  monthly  installment  herein,
             based upon a thirty (30) day month.  Said  rental  shall be paid to
             Landlord without  deduction or offset in lawful money of the United
             States  of  America,  which  shall be legal  tender  at the time of
             payment at 100 Smith Ranch Road, Suite 325, San Rafael,  California
             94903,  or to such other  place as  Landlord  may from time to time
             designate in writing.

             See Addendum to Lease, P. 5, Free Rent.

       B.    RENT  ESCALATIONS  Commencing  on the  12th  month  of  this  lease
             (December 1, 1995) and on each annual  anniversary  following,  the
             base  rent  shall  be  adjusted  by the  increase,  if any,  in the
             Consumer Price Index of the Bureau of Labor Statistics of the U. S.
             Department    of   Labor    for   All    Urban    Consumers,    San
             Francisco-Oakland-San Jose (1984=100),  "All Items" herein referred
             to as "C.P.I."

             The C.P.I.  increase shall be calculated as follows:  The base rent
             payable for the first month term of this lease shall be  multiplied
             by the percentage  change in the C.P.I. for the 12 months preceding
             December  1, 1995.  On each  anniversary  following,  the base rent
             shall be multiplied by the percentage  change in the C.P.I. for the
             12 months  preceding.  No single  increase  shall  exceed 4% of the
             previous  year's  rental rate and in 




             no event shall the new monthly  rent be less than the rent  payable
             for the month immediately preceding the date for rent adjustment.

6.     SECURITY  DEPOSIT  Tenant shall  deposit with Landlord the sum of Seventy
       Thousand Five Hundred Twenty-two Dollars  ($70,522.00),  on or before the
       Date of Possession,  See Addendum to LeaseP. 3. Said sum shall be held by
       Landlord as security  for the faithful  performance  by Tenant of all the
       terms,  covenants,  and conditions of this Lease to be kept and performed
       by Tenant during the term hereof.  If Tenant defaults with respect to any
       provision  of this Lease  including,  but not limited to, the  provisions
       relating to the payment of rent,  Landlord may (but shall not be required
       to) use, apply or retain all or any part of this security deposit for the
       payment of any rent or any other sum in  default,  or for the  payment of
       any  amount  which  Landlord  may spend or become  obligated  to spend by
       reason of Tenant's  default to compensate  Landlord for any other loss or
       damage which  Landlord may suffer by reason of Tenant's  default.  If any
       portion of said deposit is so used or applied,  Tenant shall, within five
       (5) days after written demand therefor,  deposit cash with Landlord in an
       amount  sufficient to restore the security deposit to its original amount
       and Tenant's  failure to do so shall be a material  breach of this Lease.
       Landlord  shall not be required to keep this  security  deposit  separate
       from its  general  fund and Tenant  shall not be  entitled to interest on
       such  deposit.  If  Tenant  shall  fully  and  faithfully  perform  every
       provision of this Lease to be  performed  by it, the security  deposit or
       any balance  thereof  shall be  returned  to Tenant  (or,  at  Landlord's
       option,  to the last  assignee of  Tenant's  interest  hereunder)  at the
       expiration of the Lease term. In the event of  termination  of Landlord's
       interest  in  this  Lease,   Landlord  shall  transfer  said  deposit  to
       Landlord's successor in interest.

7.     OPERATING  EXPENSE  ADJUSTMENTS  For the  purposes of this  Article,  the
       following terms are defined as follows:

       BASE YEAR             The Base Year shall be 1995.

       COMPARISON YEAR       Each calendar year of the term after the Base Year.

       DIRECT EXPENSES       All direct costs of operation and  maintenance,  as
                             determined   by  standard   accounting   practices,
                             including   the   following   costs   by   way   of
                             illustration,  but not be limited to: real property
                             taxes and  assessments;  rent taxes,  gross receipt
                             taxes,  (whether  assessed  against the Landlord or
                             assessed  against the Tenant and  collected  by the
                             Landlord,   or  both);  water  and  sewer  charges;
                             insurance premiums; utilities; janitorial services;
                             labor;  costs  incurred  in the  management  of the
                             Building;  air  conditioning  &  heating;  elevator
                             maintenance;  supplies;  materials;  equipment  and
                             tools;  and  maintenance,  costs and  upkeep of all
                             parking and common areas.  ("Direct Expenses" shall
                             not include  depreciation  on the Building of which
                             the Premises are a part or equipment therein,  loan
                             payments,   executive   salaries   or  real  estate
                             broker's commissions.)

       If the  Direct  Expenses  paid  or  incurred  by  the  Landlord  for  the
       Comparison  Year  on  account  of the  operation  or  maintenance  of the
       Building  of which the  Premises  are a part are in excess of the  Direct
       Expenses  paid or incurred  for the Base Year,  then the Tenant shall pay
       33.90% of the  increase.  This  percentage  is that  portion of the total
       rentable area of the Building occupied by the Tenant hereunder.  Landlord
       shall  endeavor  to give to Tenant on or before the first day of March of
       each year  following the  respective  Comparison  Year a statement of the
       increase in rent payable by Tenant hereunder,  but failure by Landlord to
       give  such  statement  

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       by said date shall not  constitute  a waiver by  Landlord of its right to
       require an increase in rent.  Upon receipt of the statement for the first
       Comparison  Year,  Tenant  shall  pay in full  the  total  amount  of the
       increase due for the first  Comparison Year and, in addition for the then
       current  year,  the  amount  of any  such  increase  shall  be used as an
       estimate  for said  current  year and this amount  shall be divided  into
       twelve (12) equal monthly  installments and Tenant shall pay to Landlord,
       concurrently with the regular monthly rent payment next due following the
       receipt of such statement, an amount equal to one (1) monthly installment
       multiplied  by the number of months from January in the calendar  year in
       which said  statement  is submitted  to the month of such  payment,  both
       months inclusive.  Subsequent  installments shall be payable concurrently
       with the regular  monthly rent  payments for the balance of that calendar
       year and shall continue  until the next  Comparison  Year's  statement is
       rendered.  If the next or any  succeeding  Comparison  Year  results in a
       greater  increase in Direct  Expenses,  then upon  receipt of a statement
       from  Landlord,  Tenant shall pay a lump sum equal to such total increase
       in Direct  Expenses  over the Base  Year,  less the total of the  monthly
       installments  to be paid for the next  year,  following  said  Comparison
       Year,  shall be adjusted to reflect such  increase.  If in any Comparison
       Year the  Tenant's  share of Direct  Expenses be less than the  preceding
       year, then upon receipt of Landlord's statement,  any overpayment made by
       Tenant on the monthly  installment basis provided above shall be credited
       towards  the next  monthly  rent  falling due and the  estimated  monthly
       installments  of Direct  Expenses to be paid shall be adjusted to reflect
       such lower Direct Expenses for the most recent Comparison Year.

       Even though the term has  expired  and Tenant has  vacated the  Premises,
       when the final determination is made of Tenant's share of Direct Expenses
       for the year in which this Lease terminates, Tenant shall immediately pay
       any increase due over the  estimated  expenses  paid and  conversely  any
       overpayment made in the event said expenses decrease shall be immediately
       rebated by Landlord to Tenant.

       Notwithstanding  anything contained in this Article,  the rent payable by
       Tenant  shall in no event be less than the rent  specified  in  Article 5
       above.

       See Addendum to Lease, P. 6,  Operating Expense Adjustments.

8.     USE Tenant shall use the Premises for general  office  purposes and shall
       not use or permit the Premises to be used for any other purposes  without
       the prior written consent of Landlord.

       General  office  purposes  shall be defined for purposes of this Lease to
       include computer rooms of any size required by Tenant.

       Tenant  shall  not do or  permit  anything  to be  done in or  about  the
       Premises  nor  bring  or  keep  anything  therein  which  will in any way
       increase the existing rate of or affect any fire or other  insurance upon
       the  Building  or any of  its  contents,  or  cause  cancellation  of any
       insurance policy covering said Building or any part thereof or any of its
       contents.  Tenant shall not do or permit  anything to be done in or about
       the Premises  which will in any way obstruct or interfere with the rights
       of other  tenants or occupants of the Building on injure or annoy them or
       use or allow the Premises to be used for any improper,  immoral, unlawful
       or objectionable  purpose, nor shall Tenant cause, maintain or permit any
       nuisance in, on or about the Premises.  Tenant shall not commit or suffer
       to be committed any waste in or upon the Premises.


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9.     COMPLIANCE  WITH LAW Tenant shall not use the Premises or permit anything
       to be done in or about the Premises  which will in any way conflict  with
       any law,  statute,  ordinance or  governmental  rule or regulation now in
       force or which may hereafter be enacted or promulgated.  Tenant shall, at
       its sole cost and  expense,  promptly  comply  with all  laws,  statutes,
       ordinances and governmental  rules now in force or which may hereafter be
       in  force,  and  with the  requirements  of any  board of fire  insurance
       underwriters  or  other  similar  bodies  now or  hereafter  constituted,
       relating  to,  or  affecting  the  condition,  use  or  occupancy  of the
       Premises,  excluding  changes  not  related to or  affected  by  Tenant's
       improvements or acts. The judgment of any court of competent jurisdiction
       or the admission of Tenant in any action against Tenant, whether Landlord
       be a party  thereto or not,  that Tenant has violated  any law,  statute,
       ordinance or  governmental  rule,  regulation  or  requirement,  shall be
       conclusive of that fact as between the Landlord and Tenant.

10.    ALTERATIONS AND ADDITIONS  Tenant shall not make or suffer to be made any
       alterations,  additions or improvements to or of the Premises or any part
       thereof  without the written  consent of Landlord first had and obtained.
       Any  alterations,  additions  or  improvements  to  or of  said  Premises
       including,  but not limited to, wallcovering,  paneling, air conditioning
       units and built-in  cabinet  work,  but excepting  movable  furniture and
       trade fixtures,  shall on the expiration of the term become a part of the
       realty  and  belong to the  Landlord  and shall be  surrendered  with the
       Premises.   In  the  event  Landlord   consents  to  the  making  of  any
       alterations,  additions or  improvements  to the Premises by Tenant,  the
       same shall be made by Tenant at Tenant's  sole cost and expense,  and any
       contractor or persons, selected by the Tenant to make the same must first
       be  approved  in  writing by the  Landlord.  Such  approval  shall not be
       unreasonably  withheld.  Upon the expiration or sooner termination of the
       term hereof,  Tenant shall, upon written demand by Landlord,  which shall
       be given at the time Landlord  approves the tenant  improvement  work, at
       Tenant's  sole cost and expense,  forthwith  and with all due  diligence,
       remove  any  alterations,  additions,  or  improvements  made by  Tenant,
       designated  by Landlord to be removed,  and Tenant  shall,  forthwith and
       with all due diligence at its sole cost and expense, repair any damage to
       the Premises caused by such removal.

11.    REPAIRS

       A.    By taking  possession  of the  Premises,  Tenant shall be deemed to
             have  accepted  the  Premises  as being in  good,  sanitary  order,
             condition  and repair.  Tenant  shall,  at  Tenant's  sole cost and
             expense, keep the Premises and every part thereof in good condition
             and repair damage thereto from causes beyond the reasonable control
             of Tenant with ordinary wear and tear  excepted.  Tenant shall upon
             the expiration or sooner termination of this Lease hereof surrender
             the Premises to the Landlord in good  condition,  ordinary wear and
             tear and damage from causes beyond the reasonable control of Tenant
             excepted.  Except as specifically  provided in an addendum, if any,
             to this Lease,  Landlord  shall have no  obligation  whatsoever  to
             alter, remodel,  improve, repair, decorate or paint the Premises or
             any part thereof once the initial tenant improvements are completed
             and  the  parties   hereto   affirm  that   Landlord  has  made  no
             representations  to Tenant respecting the condition of the Premises
             or the Building except as specifically herein set forth.

       B.    Notwithstanding  the  provisions  of  Article  11. A.  hereinabove,
             Landlord shall repair and maintain the  structural  portions of the
             Building,  including the basic plumbing, air conditioning,  heating
             and electrical  systems  installed or furnished by Landlord  unless
             such  maintenance and repairs are caused in part or in whole by the
             act,  neglect,  fault or 

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             omission of any duty by the Tenant, its agents, servants, employees
             or  invitees,  in which  case  Tenant  shall  pay to  Landlord  the
             reasonable cost of such maintenance and repairs. Landlord shall not
             be liable for any  failure  to make any such  repairs or to perform
             any   maintenance   unless  such  failure   shall  persist  for  an
             unreasonable  time after written notice of the need of such repairs
             or maintenance  is given to Landlord by Tenant.  Except as provided
             in Article 22 hereof,  there shall be no  abatement  of rent and no
             liability  of Landlord  by reason of any injury to or  interference
             with  Tenant's  business  arising  from the making of any  repairs,
             alterations or improvements in or to any portion of the Building or
             the  Premises,  or in or to fixtures,  appurtenances  and equipment
             therein.  Tenant  waives the right to make  repairs  at  Landlord's
             expense  under any law,  statute or  ordinance  now or hereafter in
             effect, (including the provisions of California Civil Code Sections
             1941 and 1942 and any  successor  sections or statutes of a similar
             nature); provided, however, if Landlord fails to perform any repair
             work required of Landlord with respect to the Premises  pursuant to
             this  Paragraph,  within thirty (30) days after  Landlord  receives
             Tenant's written notice of the need for such repair (or such period
             of time in excess of thirty  (30) days as is  reasonably  necessary
             based upon the nature of the required  work),  then Tenant shall be
             permitted  to  make  such  repairs,  using  contractors  reasonably
             approved by Landlord,  provided (i) Tenant first gives  Landlord an
             additional  two (2) business days prior written  notice  indicating
             that Tenant  intends to undertake  such repair,  and (ii)  Landlord
             fails to commence  such repair  within  such two (2)  business  day
             period.  If Tenant  performs  any  repair as  permitted  under this
             Paragraph,  Landlord agrees to reimburse Tenant for the reasonable,
             actual and documented costs of such repair performed by Tenant, but
             without  any  off-set  rights  against  rent or any  other  amounts
             payable by Tenant under this Lease.  Any repair work done by Tenant
             shall be done in  accordance  with the  provisions  of this  Lease,
             including  without  limitation,  Paragraph 12, keeping the premises
             free from liens.

12.    LIENS  Tenant  shall  keep the  Premises  and the  property  in which the
       Premises  are  situated  free  from  any  liens  arising  out of any work
       performed,   materials  furnished  or  obligations  incurred  by  Tenant.
       Landlord  may  require,  at  Landlord's  sole  option,  that Tenant shall
       provide  to  Landlord,  at  Tenant's  sole cost and  expense,  a lien and
       completion bond in an amount equal to one and one-half  (1-1/2) times any
       and all estimated  cost of any  improvements,  additions or alteration in
       the Premises to insure Landlord  against any liability for mechanics' and
       materialmen's liens and to insure completion of the work.

13.    ASSIGNMENT  AND  SUBLETTING  Tenant  shall not either  voluntarily  or by
       operation of law, assign,  transfer,  mortgage,  pledge, or encumber this
       Lease or any interest therein,  and shall not sublet the said Premises or
       any part  thereof,  or any right or  privilege  appurtenant  thereto,  or
       suffer any other person (the employees,  agents, servants and invitees of
       Tenant  excepted)  to  occupy  or use the said  Premises  or any  portion
       thereof,  without  written  consent of Landlord  first had and  obtained,
       which consent shall not be unreasonably withheld;  provided however, that
       Landlord in the exercise of its good faith  business  judgment may refuse
       to approve the assignment or sublease and shall  promptly  provide Tenant
       with the reasons for its refusal.  In the event Tenant  desires to assign
       this Lease or any interest therein or sublet all or part of the Premises,
       Tenant shall give Landlord  written  notice  thereof,  which notice shall
       include  (i) the name of the  proposed  assignee,  subtenant  or occupant
       ("Transferee"),  (ii)  reasonable  financial  information  regarding  the
       Transferee,  (iii)  a  description  of the  Transferee's  business  to be
       carried  on in the  Premises,  and (iv) the  terms of the  assignment  or
       sublease and a description of the portion of the Premises to be affected.
       Tenant shall also provide Landlord such additional  information regarding
       the  Transferee  or the proposed  assignment  or sublease as Landlord may
       reasonably request.

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       Notwithstanding  the foregoing,  Tenant shall have the right to assign or
       sublet the premises,  or a portion thereof,  to a wholly owned affiliated
       company or subsidiary,  without the Landlord's  consent.  Tenant shall be
       required,  however, to give written notice to Landlord in advance of such
       assignment or sublet and to prepare  assignment  or sublet  agreements on
       forms that are  reasonably  satisfactory  to Landlord.  In no event shall
       such assignment or sublet release Tenant from its  obligations  under the
       terms of this Lease.

       Consent to one  assignment,  subletting,  occupation  or use by any other
       person  shall not be deemed to a consent  to any  subsequent  assignment,
       subletting,  occupation  or use by  another  person.  Any  assignment  or
       subletting  without such consent shall be void, and shall,  at the option
       of the Landlord, constitute a default under this Lease.

14.    HOLD HARMLESS Tenant shall indemnify and hold harmless  Landlord  against
       and from any and all claims arising from Tenant's use of Premises for the
       conduct of its business or from any  activity,  work or other thing done,
       permitted or suffered by the Tenant in or about the  Building,  and shall
       further indemnify and hold harmless Landlord against and from any and all
       claims  arising  from any  breach or default  in the  performance  of any
       obligation  on  Tenant's  part to be  performed  under  the terms of this
       Lease,  or  arising  from any act or  negligence  of the  tenant,  or any
       officer,  agent,  employee,  guest or  invitee  of  Tenant,  and from and
       against all cost,  attorney's fees, expenses and liabilities  incurred in
       or about any such claim or any action or proceeding  brought  thereon and
       in any case,  action or proceeding  brought against Landlord by reason of
       any such claim. Tenant upon notice from Landlord shall defend the same at
       Tenant's expense by counsel reasonably  satisfactory to Landlord.  Tenant
       as a material part of the  consideration  to Landlord  hereby assumes all
       risk of damage to property  or injury to  persons,  in, upon or about the
       Premises, from any cause other than Landlord's negligence or willful act,
       and Tenant hereby waives all claims in respect thereof against Landlord.

       Landlord  or its agents  shall not be liable  for any damage to  property
       entrusted  to employees  of the  Building,  nor for loss or damage to any
       property  by theft or  otherwise,  nor for any  injury  to or  damage  to
       persons or property  resulting  from fire,  explosion,  falling  plaster,
       steam,  gas,  electricity,  water or rain which may leak  dampness or any
       other cause  whatsoever,  unless  caused by or due to the  negligence  or
       willful acts of Landlord, its agents,  servant or employees.  Landlord or
       its agents shall not be liable for  interference  with the light or other
       incorporeal hereditaments, less of business by Tenant, nor shall Landlord
       be liable  for any  latent  defect in the  premises  or in the  Building.
       Tenant shall give prompt  notice to Landlord in case of fire or accidents
       in the  Premises  or in the  Building  or of  defects  therein  or in the
       fixtures or equipment.

15.    SUBROGATION  Landlord and Tenant hereby  mutually waive their  respective
       rights of  recovery  against  each  other for any loss  insured  by fire,
       extended coverage and other property  insurance policies existing for the
       benefit of the  respective  parties.  Each party shall obtain any special
       endorsements,  if required by their insurer to evidence  compliance  with
       the aforementioned waiver.

16.    LIABILITY INSURANCE Tenant shall, at Tenant's expense, obtain and keep in
       force  during  the  term of this  Lease,  (1) a policy  of  comprehensive
       general  liability  insurance  insuring  Landlord and Tenant  against any
       liability arising out of the ownership,  use, occupancy or maintenance of
       the Premises and all areas appurtenant  thereto. (2) workers compensation
       insurance  as may be  required  by  law,  and  (3)  "all  risk"  property
       insurance on 

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       Tenant's   above-standard   tenant   improvements   (specifically   those
       improvements  exceeding the Landlord's  tenant  improvement  allowance as
       defined  in  Addendum  to LeaseP.  1.C),  personal  property,  equipment,
       furniture and fixtures.  The limit of said insurance shall not,  however,
       limit the  liability  of the  Tenant  hereunder.  Tenant  may carry  said
       insurance under a blanket policy,  providing,  however, said insurance by
       Tenant shall have a Landlord's  protective liability endorsement attached
       thereto.  If Tenant  shall fail to procure and maintain  said  insurance,
       Landlord  may, but shall not be required to,  procure and maintain  same,
       but at the expense of Tenant.  Insurance required hereunder,  shall be in
       companies  rated A+ AAA or better in  "Best's  Insurance  Guide."  Tenant
       shall  deliver to Landlord  prior to occupancy of the Premises  copies of
       policies  of  liability   insurance   required   herein  or  certificates
       evidencing  the existence and amounts of such insurance with loss payable
       clauses  reasonably   satisfactory  to  Landlord.   No  policy  shall  be
       cancelable or subject to reduction of coverage except after ten (10) days
       prior written notice to Landlord.

17.    SERVICES  AND  UTILITIES  See  Addendum  to  Lease,  P. 9,  Services  and
       Utilities.

18.    PROPERTY TAXES Tenant shall pay, or cause to be paid, before delinquency,
       any and all taxes levied or assessed and which become  payable during the
       term  hereof  upon  all  Tenant's  leasehold   improvements,   equipment,
       furniture, fixtures and personal property located in the Premises; except
       that  which has been paid for by  Landlord,  and is the  standard  of the
       Building. In the event any or all of the Tenant's leasehold improvements,
       equipment,  furniture,  fixtures and personal  property shall be assessed
       and taxed with the  Building,  Tenant  shall pay to Landlord its share of
       such taxes within ten (10) days after delivery to Tenant by Landlord of a
       statement in writing setting forth the amount of such taxes applicable to
       Tenant's property.

19.    RULES AND REGULATIONS Tenant shall faithfully observe and comply with the
       reasonable  rules and  regulations  that Landlord shall from time to time
       promulgate.  Landlord  reserves  the right  from time to time to make all
       reasonable  modifications to said rules. The additions and  modifications
       to those  rules shall be binding  upon Tenant upon  delivery of a copy of
       them to Tenant.  Landlord shall not be responsible for the nonperformance
       of any said  rules by any  other  tenants  or  occupants.  The  rules and
       regulations  shall be applied  equally to all tenants  occupying  Regency
       Center.

20.    HOLDING OVER If Tenant  remains in possession of the Premises or any part
       thereof after the expiration of the term hereof, with the express written
       consent  of   Landlord,   such   occupancy   shall  be  a  tenancy   from
       month-to-month at a rental in the amount of the last monthly rental, plus
       all  other  charges  payable  hereunder,  and upon all the  terms  hereof
       applicable to a month-to-month tenancy.

21.    ENTRY BY LANDLORD  Landlord  reserves and shall at any and all times have
       the right to enter the  Premises,  inspect  the same,  supply  janitorial
       service  and any other  service  to be  provided  by  Landlord  to Tenant
       hereunder,  to submit said Premises to prospective purchasers or tenants,
       to post notices of  non-responsibility,  and to alter,  improve or repair
       the  Premises and any portion of the Building of which the Premises are a
       part that Landlord may deem necessary or desirable,  without abatement of
       rent and may for that  purpose  erect  scaffolding  and  other  necessary
       structures where  reasonably  required by the character of the work to be
       performed,  always  providing that the entrance to the Premises shall not
       be blocked thereby, and further providing that the business of the Tenant
       shall not be interfered with unreasonably. Tenant hereby waives any claim
       for damages or for any injury or  inconvenience  to or interference  with
       Tenant's  business  any  loss of  occupancy  or  quiet  

                                       7



       enjoyment of the Premises,  and any other loss  occasioned  thereby.  For
       each of the  aforesaid  purposes,  Landlord  shall at all times  have and
       retain a key with which to unlock all of the doors in, upon and about the
       Premises,  excluding  Tenant's  vaults,  safes and files,  and  specific,
       secured,  sensitive and confidential  offices and Landlord shall have the
       right to use any and all means  which  Landlord  may deem  proper to open
       said doors in any  emergency,  in order to obtain  entry to the  Premises
       without  liability to Tenant  except for any failure to exercise due care
       for Tenant's property.  Any entry to the Premises obtained by Landlord by
       any of said means,  or  otherwise  shall not under any  circumstances  be
       construed  or  deemed to be a  forcible  or  unlawful  entry  into,  or a
       detainer of, the Premises,  or an eviction of Tenant from the Premises or
       any portion thereof.

22.    RECONSTRUCTION  In the event the  Premises  or the  Building of which the
       Premises  are a part are  damaged  by fire or  other  perils  covered  by
       extended  coverage  insurance,  Landlord  agrees to forthwith  repair the
       same,  and this Lease shall remain in full force and effect,  except that
       Tenant shall be entitled to a  proportionate  reduction of the rent while
       such  repairs are being made,  such  proportionate  reduction to be based
       upon the  extent to which the  making of such  repairs  shall  materially
       interfere with the business carried on by the Tenant in the Premises.  If
       the  damage is due to the fault or  neglect  of Tenant or its  employees,
       there shall be no abatement of rent.

       In the event the  Premises or the  Building of which the  Premises  are a
       part are damaged as a result of any cause  other than the perils  covered
       by fire or extended  coverage  insurance,  then Landlord shall  forthwith
       repair the same provided the extent of the  destruction  be less than ten
       (10%) of the then full  replacement  cost of the Premises or the Building
       of which the Premises  are a part.  In the event the  destruction  of the
       Premises or the  Building is to an extent  greater  than ten (10%) of the
       full replacement  cost, then Landlord shall have the option (1) to repair
       or restore such damage,  this Lease  continuing in full force and effect,
       but the rent to be proportionately reduced as hereinabove in this Article
       provided; or (2) give notice to Tenant at any time within sixty (60) days
       after such damage terminating this Lease as of the date specified in such
       notice,  which  date shall be no less than  thirty  (30) and no more than
       sixty (60) days after the giving of such  notice.  In the event of giving
       such  notice,  this Lease shall  expire and all interest of the Tenant in
       the Premises shall  terminate on the date so specified in such notice and
       the Rent,  reduced by a proportionate  amount,  based upon the extent, if
       any, to which such damage materially interfered with the business carried
       on by the Tenant in the  Premises,  shall be paid up to date of said such
       termination.

       Notwithstanding  anything  to the  contrary  contained  in this  Article,
       Landlord shall not have any obligation whatsoever to repair,  reconstruct
       or restore the damage to the Premises resulting from any casualty covered
       under this Article which occurs during the last twelve (12) months of the
       term of this Lease or any extension thereof.

       Landlord  shall not be required to repair any injury or damage by fire or
       other cause, or to make any repairs to replacements of any  over-standard
       tenant  improvements  (specifically  those  exceeding  Landlord's  tenant
       improvement  allowance  as  defined  in  Addendum  to Lease  P.  1.C.) or
       Tenant's trade fixtures, equipment, furniture or personal property.

       Except for abatement of rent as provided  above,  the Tenant shall not be
       entitled to any compensation or damages from Landlord for loss of the use
       of the whole or any part of the premises,  Tenant's  personal property or
       any  inconvenience  or  annoyance  occasioned  by  such  damage,  repair,
       reconstruction or restoration.

                                       8


23.    DEFAULT  The  occurrence  of any or more of the  following  events  shall
       constitute a default and breach of this Lease by Tenant:

       A.    The vacating or  abandonment  of the Premises by Tenant,  except in
             cases when Tenant is current with all rental payments.

       B.    The  failure  by  Tenant to make any  payment  of rent or any other
             payment required to be made by Tenant  hereunder,  as and when due,
             where such  failure  shall  continue  for a period of ten (10) days
             after written notice thereof by Landlord to Tenant.

       C.    The failure by Tenant to observe or perform  any of the  covenants,
             conditions  or provisions of this Lease to be observed or performed
             by the Tenant,  other than described in Article 23.B. above,  where
             such failure shall  continue for a period of thirty (30) days after
             written  notice thereof by Landlord to Tenant;  provided,  however,
             that if the  nature  of  Tenant's  default  is such  that more than
             thirty (30) days are reasonably  required for its cure, then Tenant
             shall not be deemed to be in default if Tenant  commences such cure
             within  said  thirty  (30) day  period  and  thereafter  diligently
             prosecutes such cure to completion.

       D.    The  making  by  Tenant  of  any  general   assignment  or  general
             arrangement  for the  benefit  of  creditors,  or the  filing by or
             against Tenant of a petition to have Tenant adjudged a bankrupt, or
             a petition or  reorganization or arrangement under any law relating
             to  bankruptcy  (unless,  in the case of a petition  filed  against
             Tenant,  the same is  dismissed  within  sixty (60)  days);  or the
             appointment  of a  trustee  or a  receiver  to take  possession  of
             substantially  all of Tenant's assets located at the Premises or of
             Tenant's  interest in this Lease,  where possession is not restored
             to Tenant within thirty (30) days; or the attachment,  execution or
             other  judicial  seizure of  substantially  all of Tenant's  assets
             located at the  Premises  or of Tenant's  interests  in this Lease,
             where such seizure is not discharged in thirty (30) days.

24.    REMEDIES IN DEFAULT In the event of any such  material  default or breach
       by Tenant, Landlord may at any time thereafter, with or without notice or
       demand and without limiting Landlord in the exercise of a right or remedy
       which Landlord may have by reason of such default or breach:

       A.    Terminate  Tenant's  right to  possession  of the  Premises  by any
             lawful means,  in which case this Lease shall  terminate and Tenant
             shall immediately surrender possession of the Premises to Landlord.
             In such event Landlord shall be entitled to recover from Tenant all
             damages  incurred by necessary  renovation  and  alteration  of the
             Premises,  reasonable  attorney's fees, any real estate  commission
             actually  paid,  the worth at the time of award by the court having
             jurisdiction thereof of the amount by which the unpaid rent for the
             balance of the term after the time of such award exceeds the amount
             of such rental loss for the same period that Tenant proves could be
             reasonably avoided,  that portion of the leasing commission paid by
             Landlord and applicable to the unexpired term of this Lease. Unpaid
             installments  of rent or other sums shall  bear  interest  from the
             date due at the rate of ten (10%)  percent per annum.  In the event
             Tenant shall have  abandoned the Premises,  Landlord shall have the
             option of (a) taking possession of the Premises and recovering from
             Tenant the amount  specified in this  paragraph,  or (b) proceeding
             under the provisions of the following Article 24.B.

                                       9


       B.    Maintain  Tenant's  right to  possession,  in which case this Lease
             shall continue in effect whether or not Tenant shall have abandoned
             the Premises.  In such event  Landlord shall be entitled to enforce
             all of Landlord's  right and remedies  under this Lease,  including
             the right to recover the rent as it becomes due hereunder.

       C.    Pursue any other  remedy now or  hereafter  available  to  Landlord
             under  the laws or  judicial  decision  of the  State in which  the
             Premises are located.

25.    EMINENT  DOMAIN If more than  twenty-five  (25%)  percent of the Premises
       shall be taken or appropriated  by any public or  quasi-public  authority
       under the power of eminent  domain,  either  party  hereto shall have the
       right,  at its option,  to terminate  this Lease,  and Landlord  shall be
       entitled  to any and all  income,  rent,  award or any  interest  therein
       whatsoever  which may be paid or made in  connection  with such public or
       quasi-public  use or  purpose,  and Tenant  shall  have no claim  against
       Landlord  for the value of any  unexpired  term of this Lease.  If either
       less than or more than  twenty-five  (25%)  percent  of the  Premises  is
       taken,  and neither  party elects to terminate  as herein  provided,  the
       rental thereafter to be paid shall be equitably  reduced.  If any part of
       the Building  other than the  Premises  may be so taken or  appropriated,
       Landlord  shall have the right at its option to terminate  this Lease and
       shall be entitled to the entire award as above provided.  Notwithstanding
       the  foregoing,   Tenant  shall  be  entitled  to  that  portion  of  any
       condemnation  award made  specifically on account of Tenant's  relocation
       expenses,  increased  rental costs,  improvements  contracted at Tenant's
       expense or disruption of Tenant's business.

26.    OFFSET  STATEMENT Tenant shall at any time and from time to time upon not
       less than ten (10) days  prior  written  notice  from  Landlord  execute,
       acknowledge and deliver to Landlord a statement in writing (a) certifying
       that this  Lease is  unmodified  and in full  force and  effect  (or,  if
       modified,  stating the nature of such  modification  and certifying  that
       this Lease as so  modified  is in full force and  effect) and the date to
       which the rental and other  charges are paid in advance,  if any, and (b)
       acknowledging  that there are not,  to  Tenant's  knowledge,  any uncured
       defaults  on the  part  of the  Landlord  hereunder  or  specifying  such
       defaults if any are claimed. Any such statement may be relied upon by any
       prospective  purchaser or  encumbrancer of all or any portion of the real
       property of which the Premises are a part.

27.    PARKING  Tenant shall have the right to use in common with other  tenants
       or occupants of the Building the parking facilities of the Building.

28.    AUTHORITY OF PARTIES

       A.    Corporate  Authority.  If Tenant is a corporation,  each individual
             executing this Lease on behalf of said  corporation  represents and
             warrants  that he is duly  authorized  to execute and deliver  this
             Lease on  behalf of said  corporation,  in  accordance  with a duly
             adopted resolution of the board of directors of said corporation or
             in accordance with the by-laws of said  corporation,  and that this
             Lease is  binding  upon said  corporation  in  accordance  with its
             terms.

       B.    Limited   Partnerships.   If  the  Landlord  herein  is  a  limited
             partnership,  it is understood and agreed that any claims by Tenant
             on  Landlord  shall  be  limited  to  the  assets  of  the  limited
             partnership,  and furthermore,  Tenant expressly waives any and all
             rights to proceed against the individual  partners or the officers,
             directors or shareholders of any corporate  partner,  except to the
             extent of their interest in said limited partnership.

                                       10


29.    GENERAL PROVISIONS

       A.    Plats and Riders.  Clauses, plats and riders, if any, signed by the
             Landlord  and the Tenant and  endorsed  on or affixed to this Lease
             are a part hereof.

       B.    Waiver.  The waiver by Landlord of any term,  covenant or condition
             herein  contained  shall not be deemed to be a waiver of such term,
             covenant or condition on any  subsequent  breach of the same or any
             other term, covenant or condition herein contained.  The subsequent
             acceptances of rent hereunder by Landlord shall not be deemed to be
             a waiver of any preceding breach by Tenant of any term, covenant or
             condition  of this  Lease,  other than the failure of the Tenant to
             pay the  particular  rental so accepted,  regardless  of Landlord's
             knowledge of such preceding breach at the time of the acceptance of
             such rent.

       C.    Notices. All notices and demands which may or are to be required or
             permitted to be given by either party to the other  hereunder shall
             be in  writing.  All  notices  and  demands by the  Landlord to the
             Tenant  shall  be sent by  United  States  Mail,  postage  prepaid,
             addressed  to the Tenant at 120 North  Redwood  Drive,  San Rafael,
             California  94903,  or to such other places as Tenant may from time
             to time  designate  in a notice to the  Landlord.  All  notices and
             demands  by the  Tenant  to the  Landlord  shall be sent by  United
             States  Mail,  postage  prepaid,  addressed  to the Landlord at 100
             Smith Ranch Road,  Suite 325, San Rafael,  California  94903, or to
             such other  person or place as the  Landlord  may from time to time
             designate in a notice to the Tenant.

       D.    Joint Obligation.  If there be more than one Tenant the obligations
             hereunder imposed upon Tenants shall be joint and several.

       E.    Marginal Headings. The marginal headings and titles to the Articles
             of this Lease are not a part of this Lease and shall have no effect
             upon the construction or interpretation of any part hereof.

       F.    Time.  Time is of the essence of this Lease and each and all of its
             provisions in which performance is a factor.

       G.    Successors  and  Assigns.   The  covenants  and  conditions  herein
             contained, subject to the provisions as to assignment, apply to and
             bind the heirs, successors,  executors,  administrators and assigns
             of the parties hereto.

       H.    Recordation. Neither Landlord nor Tenant shall record this Lease or
             a short form memorandum hereof without the prior written consent of
             the other party.

       I.    Quiet  Possession.  Upon Tenant paying the rent reserved  hereunder
             and observing and performing  all of the covenants,  conditions and
             provisions on Tenant's part to be observed and performed hereunder,
             Tenant shall have quiet  possession  of the Premises for the entire
             term hereof, subject to all the provisions of this Lease.

       J.    Late  Charges.  Tenant  hereby  acknowledges  that late  payment by
             Tenant to Landlord of rent or other sums due  hereunder  will cause
             Landlord to incur costs not  contemplated by this Lease,  the exact
             amount of which will be  extremely  difficult  to  ascertain.  Such
             costs  include,  but are not limited to,  processing and accounting
             charges,  and late charges  


                                       11


             which may be imposed  upon  Landlord  by terms of any  mortgage  or
             trust deed covering the Premises.  Accordingly,  if any installment
             of  rent or of a sum due  from  Tenant  shall  not be  received  by
             Landlord  or  Landlord's  designee  within ten (10) days after said
             amount is past due, then Tenant shall pay to Landlord a late charge
             equal to five (5%)  percent of such  overdue  amount.  The  parties
             hereby agree that such late charges represent a fair and reasonable
             estimate of the cost that Landlord will incur by reason of the late
             payment  by Tenant.  Acceptance  of such late  charges by  Landlord
             shall in no event  constitute  a waiver of  Tenant's  default  with
             respect  to  such  overdue  amount,   nor  prevent   Landlord  from
             exercising any of the other rights and remedies granted hereunder.

       K.    Prior Agreements.  This Lease contains all of the agreements of the
             parties  hereto with respect to any matter  covered or mentioned in
             this Lease, and no prior agreements or understanding  pertaining to
             any such matters shall be effective  for any purpose.  No provision
             of this Lease may be amended or added to except by an  agreement in
             writing signed by the parties hereto or their respective successors
             in  interest.  This Lease shall not be  effective or binding on any
             party until fully executed by both parties hereto.

       L.    Inability to Perform.  This Lease and the obligations of the Tenant
             hereunder shall not be affected or impaired because the Landlord is
             unable to fulfill any of its obligations hereunder or is delayed in
             doing so, if such inability or delay is caused by reason of strike,
             labor  troubles,  acts  of  God,  or any  other  cause  beyond  the
             reasonable control of the Landlord.

       M.    Attorney's  Fees. In the event of any action or proceeding  brought
             by either party  against the other under this Lease the  prevailing
             party shall be entitled to recover all costs and expenses including
             the fees of its  attorneys  in such  action or  proceeding  in such
             amount as the court may adjudge reasonable as attorney's fees.

       N.    Sale of  Premises  by  Landlord.  In the  event  of any sale of the
             Building,  Landlord  shall  be and is  hereby  entirely  freed  and
             relieved of all  liability  under any and all of its  covenants and
             obligations  contained in or derived from this Lease arising out of
             any act, occurrence or omission occurring after the consummation of
             such sale; and the purchaser,  at such sale or any subsequent  sale
             of the  Premises  shall be deemed,  without any  further  agreement
             between the parties or their  successors in interest or between the
             parties and any such  purchaser to have assumed and agreed to carry
             out any and all of the  covenants and  obligations  of the Landlord
             under this lease.

       O.    Subordination Attornment. Upon request of the Landlord, Tenant will
             in  writing  subordinate  its rights  hereunder  to the lien of any
             first  mortgage,  or first  deed of trust  to any  bank,  insurance
             company or other  lending  institution,  now or  hereafter in force
             against the land and Building of which the Premises are a part, and
             upon any  buildings  hereafter  placed  upon the land of which  the
             Premises are a part,  and to all  advances  made or hereafter to be
             made upon the security thereof.

             Notwithstanding such subordination, neither Tenant's right to quiet
             possession  of the  Premises  nor this Lease shall be  disturbed or
             affected  if  Tenant  is not in  default  hereunder  and so long as
             Tenant  shall  pay the  rent and  observe  and  perform  all of the
             provisions of this Lease, unless this Lease is otherwise terminated
             pursuant to its terms.

                                       12



       P.    In the event any proceedings are brought for foreclosure, or in the
             event of the  exercise of power of sale under any  mortgage or deed
             of trust made by the  Landlord  covering the  Premises,  the Tenant
             shall attorn to the purchaser upon any such foreclosure or sale and
             recognize such purchaser as the Landlord under this Lease.

       Q.    Name.  Tenant  shall  not use the  name of the  Building  or of the
             development in which the Building is situated for any purpose other
             than as an address of the business to be conducted by the Tenant in
             the Premises.

       R.    Separability.  Any  provision of this Lease which shall prove to be
             invalid,  void  or  illegal  shall  in no  way  effect,  impair  or
             invalidate  any other  provision  hereof and such  other  provision
             shall remain in full force and effect.

       S.    Cumulative  Remedies.  No remedy  or  election  hereunder  shall be
             deemed exclusive but shall,  wherever possible,  be cumulative with
             all other remedies at law or in equity.

       T.    Choice of Law.  This  Lease  shall be  governed  by the laws of the
             State in which the Premises are located.

       U.    Signs  and  Auctions.  Tenant  shall  not  place  any sign upon the
             Premises  or  Building  or  conduct  any  auction  thereon  without
             Landlord's prior written consent.

30.    BROKERS Tenant  warrants that it has had no dealings with any real estate
       broker or agents in connection  with the negotiation of this Lease and it
       knows no real estate  broker or agent who is entitled to a commission  in
       connection with this Lease.


       THE JOSEPH AND EDA PELL                     FAIR, ISAAC AND COMPANY,
           REVOCABLE TRUST                               INCORPORATED



       By:                                         By:
       ----------------------------                -----------------------------
                Joseph Pell


       Its:                                        Its:
       ----------------------------                -----------------------------



       By:                                         Date:
       ----------------------------                -----------------------------
                 Eda Pell


       Its:
       ----------------------------



       Date:
       ----------------------------



                                       13


                              RULES AND REGULATIONS

1.     No  sign,  placard,  picture,  advertisement,  name or  placard  shall be
       inscribed,  displayed  or  printed  or  affixed  on or to any part of the
       outside or inside of the  Building  without  the  written  consent of the
       Landlord  first had and  obtained  and  Landlord  shall have the right to
       remove any such sign,  placard,  picture,  advertisement,  name or notice
       without notice to and at the expense of Tenant.

       All  approved  signs or  lettering  on doors shall be  printed,  painted,
       affixed or inscribed at the expense of Tenant by a person  approved of by
       Landlord.

       Tenant shall not place  anything or allow  anything to be placed near the
       glass of any window,  door,  partition or wall which may appear unsightly
       from outside the Premises;  provided,  however, that Landlord may furnish
       and install a Building  standard window covering at all exterior windows.
       Tenant  shall not without  prior  written  consent of  Landlord  cause or
       otherwise sunscreen any window.

2.     The sidewalks, halls, passages, exits, entrances, elevators and stairways
       shall not be  obstructed  by any of the  tenants  or used by them for any
       purpose other than for ingress and egress from their respective Premises.

3.     Tenant  shall not alter any lock or install any new or  additional  locks
       without  permission of Landlord,  whose consent shall not be unreasonably
       withheld, or any bolts on any doors or windows of the Premises.

4.     The toilet rooms,  urinals,  wash bowls and other  apparatus shall not be
       used for any purpose other than that for which they were  constructed and
       no foreign  substance of any kind whatsoever  shall be thrown therein and
       the  expense  of  any  breakage,  stoppage,  damage  resulting  from  the
       violation  of this  rule  shall  be  borne by the  Tenant  who,  or whose
       employees or invitees shall have caused it.

5.     Tenant  shall not overload the floor of the Premises or in any way deface
       the Premises or any part thereof.

6.     No furniture,  freight or equipment of any kind shall be brought into the
       Building  without the prior notice to Landlord and all moving of the same
       into or out of the Building shall be done at such time and in such manner
       as Landlord shall designate. Notwithstanding the above, Tenant shall have
       the right to move  furniture,  freight or  equipment  into and out of the
       building  without  prior notice to Landlord,  provided that such moves do
       not involve  exclusive use of an elevator for an extended period of time,
       nor does the move  interfere  with the  operation of other tenants in the
       building. Landlord shall have the right to prescribe the weight, size and
       position of all safes and other heavy equipment brought into the Building
       and  also the  times  and  manner  of  moving  the same in and out of the
       Building.  Safes or other heavy objects shall, if considered necessary by
       Landlord, stand on supports of such thickness as is necessary to properly
       distribute the weight.  Landlord will not be  responsible  for loss of or
       damage to any such safe or properly from any cause and all damage done to
       the  Building by moving or  maintaining  any such safe or other  property
       shall be repaired at the expense of the Tenant.


                                       2


7.     Tenant  shall  not  use,  keep or  permit  to be used or kept any foul or
       noxious  gas or  substance  in the  Premises,  or permit  or  suffer  the
       Premises to be occupied or used in a manner offensive or objectionable to
       the Landlord or other occupants of the Building by reason of noise, odors
       and/or  vibrations,  or interfere in any way with other  tenants or those
       having business therein,  nor shall any animals or birds be brought in or
       kept in or about the Premises or the Building.

8.     No cooking,  except for microwave and coffee  machines,  shall be done or
       permitted by any Tenant on the  Premises,  nor shall the Premises be used
       for the storage of merchandise,  for washing clothes, for lodging, or for
       any improper, objectionable or immoral purposes.

9.     Tenant  shall  not  use or  keep  in the  Premises  of the  Building  any
       kerosene,  gasoline or inflammable or combustible  fluid or material,  or
       use any method of heating or air conditioning other than that supplied by
       Landlord.

10.    Landlord  will  direct  electricians  as to where and how  telephone  and
       telegraph wires are to be introduced. No boring or cutting for wires will
       be  allowed  without  the  consent  of  the  Landlord.  The  location  of
       telephones, call boxes and other office equipment affixed to the Premises
       shall be subject to the approval of Landlord.

11.    On Saturdays,  Sundays and legal holidays,  and on other days between the
       hours of 6:00  p.m.  and 8:00  a.m.  the  following  day,  access  to the
       Building,  or to the halls,  corridors,  elevators  or  stairways  in the
       Building,  or to the  Premises may be refused  unless the person  seeking
       access is known to the person or employee  of the  Building in charge and
       has a pass or is properly  identified.  The Landlord  shall in no case be
       liable for  damages  for any error  with  regard to the  admission  to or
       exclusion  from the  Building of any person.  In case of  invasion,  mob,
       riot, public  excitement,  or other commotion,  the Landlord reserves the
       right to prevent  access to the Building  during the  continuance  of the
       same by closing of the doors or otherwise,  for the safety of the tenants
       and protection of property in the Building and the Building.

12.    Landlord  reserves  the right to exclude or expel from the  Building  any
       person who, in the  judgment of  Landlord,  is  intoxicated  or under the
       influence  of liquor or drugs,  or who shall in any  manner do any act in
       violation of any of the rules and regulations of the Building.

13.    No vending  machine or machines of any  description  shall be  installed,
       maintained or operated upon the Premises  without the written  consent of
       the Landlord.

14.    Landlord  shall have the right,  exercisable  without  notice and without
       liability  to  Tenant,  to  change  the name and  street  address  of the
       Building of which the Premises are a part.

15.    Tenant  shall not  disturb,  solicit,  or  canvass  any  occupant  of the
       Building and shall cooperate to prevent same.

16.    Without the written consent of Landlord, Tenant shall not use the name of
       the  Building in  connection  with or in  promoting  or  advertising  the
       business of Tenant except as Tenant's address.

17.    Landlord shall have the right to control and operate the public  portions
       of  the  Building,  and  the  public  facilities,  and  heating  and  air
       conditioning,  as well as facilities  furnished for the common use of the
       tenants,  in such  manner as it deems best for the benefit of the tenants
       generally.



                                       3


18.    All entrance doors in the Premises shall be left locked when the Premises
       are not in use, and all doors opening to public  corridors  shall be kept
       closed except for normal ingress and egress from the Premises.













                                       4



                             FIRST ADDENDUM TO LEASE
                                 BY AND BETWEEN
                THE JOSEPH AND EDA PELL REVOCABLE TRUST, LANDLORD
                                       AND
                  FAIR, ISAAC AND COMPANY, INCORPORATED, TENANT
                               DATED JULY 10, 1993


1.     TENANT IMPROVEMENTS

       A.    Working Drawings and Specifications  ("Bid Package"):  Tenant shall
             authorize  Richard Pollack and Associates or any other architect or
             architectural  firm of Tenant's choice  ("Architect")  to prepare a
             space plan, construction drawings and design specifications for the
             Premises.  Tenant may direct  Architect  to utilize the services of
             consultants  ("Consultants")  to provide  engineered  drawings  and
             design  specifications for the mechanical,  electrical and plumbing
             systems  in the  Premises,  including,  but not  limited to any air
             conditioning  system,  duct work, heating and electric  facilities.
             (All such architectural and engineering drawings and specifications
             are herein  referred  to  collectively  as the "Bid  Package").  In
             putting together the Bid Package,  Architect and Consultants  shall
             exert their best efforts to reuse all existing  improvements in the
             Premises   where   possible  and  in   conformance   with  Tenant's
             requirements in the Premises. Tenant shall not be required to reuse
             existing light  fixtures in the Premises,  but rather shall specify
             its own light  fixtures.  Landlord  shall provide the Architect and
             Consultants  with the base  building  capacity  for (1)  electrical
             power,  (2)  HVAC  and  (3)  floor  loading  (live  and  dead  load
             capacities and design  criteria for the Premises).  The Bid Package
             shall be  submitted  to Tenant for its review and written  approval
             which shall be evidenced by Tenant's  signing the Bid Package.  The
             Bid Package  shall also be  submitted  to Landlord  for  Landlord's
             approval  which shall also be evidenced by  Landlord's  signing the
             Bid  Package.   Landlord's   approval  shall  not  be  unreasonably
             withheld.  It is the  understanding  of  the  parties  that  Tenant
             intends to provide its  employees  with high  quality  office space
             which meets the current  needs of the  workforce  and  enhances the
             work performance of the employees and the company,  while remaining
             flexible enough to accommodate the growth and changing needs of the
             Tenant.  In other  words,  the Tenant may not always be looking for
             the most economical solution or method of construction,  but rather
             one which provides  Tenant with the highest  ability to perform its
             work while maintaining flexibility for future needs.

             All architectural design, engineering, and consulting fees shall be
             included in the Tenant Improvement Allowance.  See Addendum P. 1.C.
             Tenant  may  require  that  certain  subcontractors  be used by the
             Contractor in bidding and performing the work,  including,  but not
             limited to, WBE Electrical, WBE Telecom and Peerless Lighting.

             The Bid Package shall include the Construction Contract which shall
             be provided by Tenant.  Landlord shall have the right to review and
             approve the  Construction  Contract and make any necessary  changes
             with  respect  to  preserving  and  protecting  Landlord's  rights,
             remedies and property.



                                       1



             The Bid Package  shall be completed  and accepted by both  Landlord
             and  Tenant no later than July 1,  1994.  Each party  shall have at
             least ten (10) working days to review the Bid Package.  Tenant will
             prepare a schedule  for  delivery  and review of the Bid Package by
             January 1, 1994.

       B.    Contractor: The Contractor who shall perform the tenant improvement
             work in the Premises  shall be selected from two bidders.  Landlord
             shall select one Contractor and Tenant shall select one Contractor.
             No later than June 1, 1994,  Landlord and Tenant shall provide each
             other  with the name and  address of their  respective  Contractor.
             Landlord  shall have fourteen (14) days to evaluate the  Contractor
             selected by Tenant.  Landlord's criteria for evaluation of Tenant's
             Contractor  shall  include,  but not be limited to,  reputation and
             quality  of  workmanship,  record of  completing  previous  jobs on
             schedule  and  within  budget,  relationship  with  the City of San
             Rafael  Building  and  Planning  Departments,   cooperativeness  in
             dealing with  Landlord and its  employees,  financial  strength and
             billing procedure. Tenant shall have fourteen (14) days to evaluate
             Landlord's   Contractor.   Tenant's   criteria  for  evaluation  of
             Landlord's  Contractor  shall include,  but not be limited to, cost
             effectiveness,   quality  of  workmanship,  creativity,  record  of
             completing work on schedule and within budget, and an understanding
             of Tenant's  current  and future  requirements  and a good  working
             relationship  with  Tenant and  Tenant's  employees.  Landlord  and
             Tenant  shall  each  use  best  efforts  in  ensuring   that  their
             evaluation  process  of  each  other's   Contractors  is  fair  and
             reasonable.  A copy  of  the  Bid  Package  may be  given  to  each
             Contractor and may be used in evaluating the  Contractor.  Landlord
             and Tenant shall have the right to reject each  other's  Contractor
             based on any of the above criteria or any other relevant  criteria.
             If a Contractor is rejected, the reasons for the rejection shall be
             stated  in a letter to  Landlord  or  Tenant.  If a  Contractor  is
             rejected  by  Landlord  or  Tenant,  another  Contractor  shall  be
             selected and its name  submitted  in writing  within five (5) days.
             Each  Contractor  shall be evaluated using the same criteria stated
             above.  Neither  Tenant nor  Landlord  may  reject  more than three
             Contractors submitted by the other.

             Landlord may submit its own name as a Contractor.

             As  soon as  Landlord  approves  Tenant's  choice  of a  Contractor
             ("Tenant's  Contractor") and as soon as Tenant approves  Landlord's
             choice  of  a   Contractor   ("Landlord's   Contractor")   Tenant's
             Contractor and Landlord's  Contractor shall be requested in writing
             to submit a bid on the Bid  Package.  Ten (10)  working  days after
             receipt of the request for bid and the complete  Bid Package,  both
             Contractors shall submit a sealed fixed price contract bid (on such
             contract form as Landlord, Tenant and Architect shall designate) to
             construct  the tenant  improvements  specified  in the Bid Package.
             Landlord  and  Tenant  shall  jointly  open and  review  the  bids.
             Landlord  and  Tenant  (after   adjustments  for  any  inconsistent
             assumptions  to reflect  an  "apples-to-apples"  comparison)  shall
             select the lowest  price bidder as the  Contractor  ("Contractor").
             The Contractor shall enter into a construction contract with Tenant
             consistent  with  the  terms  of the  Bid  Package  and  its bid to
             construct  the tenant  improvements.  That contract must state that
             Tenant shall hold Landlord  harmless from any and all liability for
             the work to be  performed  under  the  terms  of that  construction
             contract.

             If Landlord's  Contractor is not selected as the successful bidder,
             Tenant  shall  pay  Landlord  or its  representative  a  reasonable
             owner's  representation fee to compensate Landlord for its time and
             effort in inspecting and overseeing the  construction of the tenant
             improvement work and assuring itself of good quality  materials and

                                       2



             workmanship,   that  the  work   contained   in  the   Request  for
             Disbursement (see Addendum P. 1.D.) is complete,  and that there is
             no interference with the day-to-day operations of the Building as a
             result of Tenant's construction. The parties agree that the maximum
             fee  chargeable by Landlord shall be $50.00 per hour for up to five
             (5) hours per week.  This fee  shall be  deducted  from the  Tenant
             Improvement Allowance (see Addendum to Lease P. 1.C.

       C.    Tenant  Improvement  Allowance:  Landlord  shall  contribute  Seven
             Hundred Sixty-two Thousand Two Hundred Twenty Dollars ($762,220.00)
             ($23.00 x 33,140 usable SF) toward the  construction  of the tenant
             improvements   for   Tenant's   Premises    ("Tenant    Improvement
             Allowance").  The Tenant  Improvement  Allowance  shall include all
             architectural,  engineering and consultant fees, and all other fees
             charged in conjunction  with  preparation  of the Bid Package.  All
             costs exceeding the Tenant Improvement  Allowance shall be borne by
             Tenant.

       D.    Disbursement of Tenant Improvement  Allowance:  Once a month, on or
             before the 10th day of the month,  Tenant shall present to Landlord
             a Request for Disbursement ("Request for Disbursement")  requesting
             payment  by  Landlord  of any  costs  associated  with the  design,
             engineering or construction of the tenant improvements. The Request
             for Disbursement shall include the following information:

             1)   A  certificate  from  Tenant  confirming  that all of the work
                  contained in the Request for  Disbursement  has been completed
                  in accordance with the applicable contracts.

             2)   A Certificate from Tenant's  Architect  confirming that all of
                  the work  contained in the Request for  Disbursement  has been
                  completed in  accordance  with the  applicable  contracts  and
                  certifying that materials have arrived on the job.

             3)   Unconditional  mechanics  lien releases and copies of invoices
                  from the Contractor, subcontractors, suppliers and materialmen
                  marked "Paid."

             4)   And such other reasonable documentation as may be requested by
                  Landlord not later than the 25th day of the previous month.

             Payment shall not be made on any Request for Disbursement until all
             of the information and documentation above is complete.

             Payment  shall be made only for  those  materials  which  have been
             installed or which have been  delivered to the  Premises.  Landlord
             shall have five (5)  calendar  days from the date of receipt of the
             Request for Disbursement to review same and request  clarification.
             If Landlord  is in  Agreement  with the  Request for  Disbursement,
             payment  shall be made to Tenant within ten (10) days of receipt of
             the Request for Disbursement. If any items are in dispute, Landlord
             shall  not make  payment  on  those  items  until  the  dispute  is
             resolved,  but Landlord shall make payment to Tenant of all amounts
             not in dispute  within ten (10) days of receipt of the  Request for
             Disbursement. Landlord shall not unreasonably withhold its approval
             of any  Request for  Disbursement  or on any  specific  request for
             payment made therein. A final disbursement of Twenty-five  Thousand
             Dollars  ($25,000.00)  shall be held until all  punchlist  items in
             Tenant's Premises are complete,  and the time for the filing of any
             mechanics  liens  claimed or which might be filed on account of any
             work performed by Tenant, Contractor, subcontractors,  suppliers or
             materialmen has passed.  Any damage to Landlord's  property will be
             repaired to  

                                       3


             Landlord's  satisfaction.  Once  Landlord has  disbursed the entire
             amount of the Tenant  Improvement  Allowance (See Addendum P. 1.C.)
             to Tenant, except the final disbursement of $25,000.00, any and all
             costs  associated  with the design,  engineering or construction of
             Tenant's Premises shall be paid directly by Tenant.

       E.    Change  Orders:  Tenant may,  but only by written  instructions  or
             drawings   issued  to  Landlord  and   Contractor   ("Change  Order
             Request"),  make changes to the work  specified in the Bid Package,
             including without limitation,  requiring additional work, directing
             the omission of work previously ordered or changing the quantity or
             type of any materials, equipment or services. Promptly upon receipt
             of a Change Order  Request,  Contractor  will provide Tenant with a
             statement  in  detail   setting  forth  the  cost  of  said  change
             (including  a  breakdown  of  costs   attributable   to  labor  and
             materials,  construction  equipment  exclusively  necessary for the
             change,  and  preparation  or amendment to shop drawings  resulting
             from said  change and any time  delays  anticipated  to result from
             said  change).  Tenant will have two (2) days after receipt of such
             statement  in  which  to  confirm  the  Change  Order  Request  and
             authorize  the work to be  performed or to withdraw  such  request.
             Change  Orders will be signed by Landlord  and Tenant in advance of
             any work being performed on a Change Order.

       F.    Substantial  Completion:  For purposes of this Lease,  "Substantial
             Completion" shall mean that construction of the tenant improvements
             has been completed in accordance  with the Bid Package,  except for
             minor finishing  details of  construction,  decoration,  mechanical
             adjustment,  minor  replacement of defective or damaged  materials,
             and  other  items  of  a  type  commonly  found  on   architectural
             punchlists,  all of  which  do not  materially  interfere  with the
             occupancy  and use of the  Premises  by  Tenant  or  with  Tenant's
             ability to complete the  improvements to the Premises to be made by
             Tenant.  Within three (3) days of Substantial  Completion Tenant's,
             Architect  shall  notify  Landlord in writing that the Premises are
             Substantially  Complete.  If Tenant is  conducting  business in any
             part of the  Premises  the  space  shall  be  automatically  deemed
             Substantially Complete.

             Within ten (10) calendar days after  Substantial  Completion of the
             tenant improvements,  Tenant, accompanied by Landlord or Landlord's
             representative,  shall  make  an  inspection  of the  Premises  and
             prepare  a  punchlist  of  items  needing  additional  work  by the
             Contractor.   Contractor   shall   complete  all  punchlist   items
             reasonably  identified  by Tenant or  Landlord  within  thirty (30)
             calendar  days  after  the  inspection  or as soon  as  practicable
             thereafter.  If there is any dispute as to whether  Contractor  has
             substantially completed the work, a good faith decision of Tenant's
             Architect shall be final and binding on the parties.

       G.    Standard of  Construction:  Contractor  shall  complete all work in
             accordance with the Bid Package approved by Landlord and Tenant and
             shall make no  alterations,  additions,  or  reinforcements  to the
             structure  of the  building  except  as  specifically  approved  by
             Landlord in the Bid package, or in writing  thereafter.  Tenant, or
             Contractor,  at its expense,  shall  procure all building and other
             permits  required for  completion of Tenant's  work.  Tenant agrees
             that all work done by Tenant,  its  Contractor  and  subcontractors
             shall be performed in full compliance with all laws, rules, orders,
             permits,  ordinances,  directions,  regulations and requirements of
             all  governmental   agencies,   offices,   and  departments  having
             jurisdiction,  including without limitation  applicable  provisions
             pertaining to use of hazardous or toxic materials and the Americans
             with  Disabilities  Act,  

                                       4



             and  in  full  compliance  with  the  rules,  orders,   directions,
             regulations and  requirements of the Board of Fire  Underwriters or
             any other organization performing a similar function.

             Landlord  shall have the right to enter the Premises at any time to
             post  any  Notice  of  Non-Responsibility  or other  notice  on the
             Premises   during   Tenant's   construction.   Contractor  and  all
             contractors  and  subcontractors  retained by Tenant or  Contractor
             shall be bondable and bonded, licensed contractors, possessing good
             labor  relations,   adequate  financials,  and  with  a  record  of
             performing quality workmanship.

             During the course of construction,  Tenant shall maintain builder's
             risk  insurance  in form and  content  reasonably  satisfactory  to
             Landlord.  Tenant's  insurance shall name Landlord as an additional
             insured  and shall  provide  that it may not be canceled or amended
             without twenty (20) days prior written notice to Landlord. At least
             seven (7)  calendar  days prior to  commencement  of  construction,
             Tenant shall provide  Landlord with a certificate of such insurance
             and  evidence  of  any  required  bonds  in  form  satisfactory  to
             Landlord.

             Contractor   shall  complete  the  tenant   improvement  work  with
             diligence and in such a manner as not to interfere  with the use or
             enjoyment  of other  portions  of the  Project  or common  areas by
             Landlord  or  other  tenants.  Contractor  shall  provide  for  all
             temporary power,  water and other utility facilities as required in
             connection with the construction of Tenant's work. Contractor shall
             provide  its  own  dumpster  for  collection  and   disposition  of
             construction  debris, which shall be located at a location approved
             by Landlord, and all construction debris from construction shall be
             disposed of in  Contractor's  dumpster and not in trash  facilities
             for  the  Project.   Contractor's  construction  materials,  tools,
             equipment and debris shall be stored only within the  Premises,  or
             in areas  designated  for that  purpose  by  Landlord.  Work  space
             exterior to the Premises  shall be available  only with the written
             approval of Landlord.  Tenant's  construction work shall be subject
             to the  inspection  and  supervision  of  Landlord  and  Landlord's
             representatives.

             Tenant and Contractor  shall  indemnify and hold harmless  Landlord
             for any and all claims arising from Tenant's work. Tenant shall pay
             for all damage to the Building,  the Project,  or appurtenant areas
             or equipment, as well as all damage to tenants or occupants thereof
             or their  licensees,  or invitees,  including,  but not limited to,
             losses  incurred as the result of power outages  caused by Tenant's
             or  Contractor's  work in the  Building.  Any such  damages  may be
             deducted from the Tenant Improvement Allowance.

       H.    Liability:   The  parties  acknowledge  that  Landlord  is  not  an
             architect or engineer and that the tenant  improvement work will be
             designed by  independent  Architects,  Engineers  and  Consultants.
             Accordingly,  Landlord  does not guarantee or warrant that any part
             of the Bid  Package  will be free  from  errors or  omissions,  and
             Landlord shall have no liability therefor.

             Tenant shall be solely responsible for the adequacy in all respects
             of the Bid Package,  including without  limitation  compliance with
             all  governmental  requirements,  compatibility  with the  building
             shell, and any special  requirements of Tenant's proposed equipment
             or machines with respect to ambient temperatures, electrical use or
             current,  or water  availability.  Landlord shall warrant only that
             the information  provided  regarding the base building (referred to
             in  Addendum  to Lease P. 1.A.) is true and  correct to the best of
             its  knowledge.   Tenant   acknowledges  that  in  connection  with
             obtaining  Landlord's  approval  of the  Bid  Package,  Tenant  may
             provide  Landlord with certain  information  

                                       5



             regarding its specific needs relating to the Premises in developing
             plans and  specifications  for  Tenant's  work and that  Tenant may
             provide some of its own equipment for installation in the Premises.
             Tenant further  acknowledges that Landlord will make no independent
             review of any such  information and that Landlord does not warrant,
             either expressly or impliedly,  the adequacy of the Bid Package for
             Tenant's  requirements or Tenant's  equipment for Tenant's intended
             purpose.

       I.    Ownership of Tenant  Improvements:  Upon  termination of the Lease,
             all of the tenant  improvements shall remain in the Premises unless
             Landlord shall consent in writing to the removal thereof by Tenant.
             However,  all Tenant's  trade  fixtures,  equipment,  furniture and
             personal property shall remain the property of Tenant.

       J.    Life Safety: With respect to Life Safety System,  Landlord believes
             to the best of its knowledge  that Regency Center meets all current
             code requirements including handicap access compliance. If any code
             requirements are not met with respect to the Building's Life Safety
             System all costs to  accomplish  changes  necessary to the Building
             shall be  covered  by  Landlord.  All code  compliance  costs  with
             respect  to  Tenant's  Premises  shall  be  covered  by the  Tenant
             Improvement Allowance or by Tenant.

       K.    Use of Current  Fixtures in Space:  Tenant  shall have the right to
             reuse the  fixtures  currently in the  Premises  including  but not
             limited  to  all  cafeteria  built-ins,   the  moveable  partitions
             (retractable wall) in the training rooms and fire extinguishers and
             cases.  The food trolley located in the cafeteria and the equipment
             purchased  or  leased by the  previous  Tenant  including,  but not
             limited  to,  the  cafeteria  tables  and  chairs,  ice  dispenser,
             training  room tables,  chairs,  white boards,  projection  screen,
             reception  desk,  counter and hutch are not part of the fixtures in
             the Premises.

3.     POSSESSION

       A.    Possession  of the  Premises  ("Possession")  shall be delivered to
             Tenant  no  later  than   October  1,  1994  for  the   purpose  of
             constructing  the tenant  improvements.  If possession of the space
             cannot be  delivered  by  Landlord  by that  date,  for any  reason
             whatsoever,  this Lease  shall not be void or  voidable,  nor shall
             Landlord  be  liable to  Tenant  for any loss or  damage  resulting
             therefrom, nor shall the expiration date of the term of Lease be in
             any way  extended,  but in that  event,  of  Commencement  Date (as
             defined in  AddendumP.  4.A.) shall be extended by the exact number
             of days of  Landlord's  delay in  delivering  possession.  Landlord
             shall inform  Tenant of the date of  Possession in writing at least
             thirty (30) days prior to Possession.

       B.    If Landlord  shall not have  delivered  Possession  of the Premises
             within ninety (90) days after the Commencement  Date (as defined in
             Addendum P. 4.A.),  Tenant  may, at Tenant's  option,  by notice in
             writing to Landlord  within ten (10) days  thereafter,  cancel this
             Lease,  in which event the  parties  shall be  discharged  from all
             obligations  hereunder;  provided,  however,  that if such  written
             notice by Tenant is not  received by Landlord  within said ten (10)
             day period,  Tenant's  right to cancel this lease  hereunder  shall
             terminate and be of no further force or effect.



                                       6



4.     COMMENCEMENT

       A.    If Possession is delivered on October 1, 1994 the Commencement Date
             ("Commencement")  shall be defined as  December 1, 1994 or five (5)
             days after  Substantial  Completion of the tenant  improvement work
             (as  defined  in  Addendum  P.  1.E.)  whichever  is  earlier.   If
             Possession is delivered prior to October 1, 1994, the  Commencement
             Date shall be sixty (60) calendar days after the date of Possession
             or  five  (5)  days  after  Substantial  Completion  of the  tenant
             improvement work, whichever is earlier.

             Landlord shall notify Tenant in writing of the actual  Commencement
             Date no later than thirty (30) days after  Substantial  Completion.
             In the event  Substantial  Completion  is delayed by Tenant  Caused
             Delays (as  defined in  Addendum  P. 4.C.) the same  number of days
             shall be deducted  from total number of days of the  build-out  and
             that date shall be the Commencement.

5.     FREE RENT

       Landlord  shall  allow  Tenant and  Contractor  to occupy and perform the
       tenant  improvement  work in the Premises  without  payment of rent after
       Possession  (as defined in Addendum P. 3) for a period of two (2) months.
       Landlord  shall allow  Tenant to occupy  one-half  (1/2) of the  Premises
       (approximately  17,630 rentable square feet) for six (6) months after the
       Commencement  Date without  payment of rent.  Tenant's first month's rent
       paid upon  execution of this Lease shall cover the rent on the  remaining
       one-half  (1/2) of the  Premises  for the first two (2) months  after the
       Commencement Date.

6.     OPERATING EXPENSE ADJUSTMENTS  (Continued from Article 7 of the Lease.)

       A.    During the  initial  term of this Lease,  management  costs for the
             building  shall not exceed  three  percent (3%) of the gross rental
             income for the building.

       B.    Landlord shall keep full,  accurate,  and separate books of account
             and records covering all Direct  Expenses,  which books of accounts
             and records shall accurately reflect the total Direct Expenses, and
             Landlord's billings to Tenant for Operating Expense Adjustments.

       C.    Tenant  shall  have the right to  protest  any  charge to Tenant by
             Landlord for  Operating  Expense  Adjustments,  provided  that said
             protest is made within thirty (30) days after receipt of Landlord's
             notice of such  charge.  In the event that  Tenant  shall  protest,
             Tenant  shall be  entitled  to audit  Landlord's  books of account,
             records,  and other pertinent data regarding Direct  Expenses.  The
             audit shall be limited to the  determination of direct Expenses and
             charges to Tenant for Operating  Expense  Adjustments  and shall be
             conducted  during normal  business  hours.  If the audit shows that
             there has been an overpayment by Tenant,  the overpayment  shall be
             immediately due and repayable by Landlord to Tenant.

7.     OPTION TO EXTEND

       A.    Landlord  grants to Tenant  the  option to extend  the term of this
             Lease for two 3-year periods commencing when the prior term expires
             upon each and all of the following terms and conditions:

                                       7



               (i)   Tenant gives to Landlord and  Landlord  receives  notice of
                     the  exercise  of the option to extend  this Lease for said
                     additional  term no later than twelve (12) months  prior to
                     the time  that the  option  period  would  commence  if the
                     option were exercised,  time being of the essence.  If said
                     notification of the exercise of said option is not so given
                     and received, this option shall automatically expire;

              (ii)   At the time said written notification of exercise of option
                     is given and received, Tenant shall not be in default under
                     any  of  the  material  obligations  of  this  Lease  to be
                     performed   by  Tenant  and  this  Lease   shall  not  have
                     previously   terminated   nor   terminated   prior  to  the
                     commencement of the option term;

             (iii)   All of the terms and  conditions of this Lease except where
                     specifically modified by this option shall apply;

              (iv)   The monthly rent for each month of the option  period shall
                     be calculated as follows:

             The rent payable by Tenant  during the first option period shall be
             the Fair Market Rental Value of the Premises (as defined  below) at
             the  commencement  date of the  option  period.  There  shall be an
             annual  C.P.I.  increase  not to exceed four  percent  (4%) in each
             subsequent  year of the first option period.  The rent in the first
             year of the second option period shall be the rent in the last year
             of the first option period to which will be added a C.P.I. increase
             not to exceed four percent  (4%).  There shall be an annual  C.P.I.
             increase not to exceed four percent (4%) in each subsequent year of
             the second option period.  All of the C.P.I.  increases  during the
             option  periods  shall be  calculated  on the basis of the  formula
             provided in the Lease P. 5.B. If Landlord  and Tenant  cannot agree
             on the Fair Market  Rental Value of the Premises for the  extension
             periods within  forty-five  (45) days after the Tenant has notified
             Landlord of its  exercise of the option,  Landlord and Tenant shall
             each select,  within forty-five (45) days of such notification,  an
             appraiser  who must be a qualified  M.A.I.  appraiser  to determine
             said Fair Market Rental  Value.  If one party fails to so designate
             an appraiser  within the time required,  the  determination of Fair
             Market Rental Value of the one appraiser who has been designated by
             the other party hereto  within the time  required  shall be binding
             upon both parties. The appraisers shall submit their determinations
             of Fair Market Rental Value to both parties within thirty (30) days
             after  their   selection.   If  the  difference   between  the  two
             determinations   is  ten  percent  (10%)  or  less  of  the  higher
             appraisal, then the average between the two determinations shall be
             the Fair Market Rental Value of the Premises. If said difference is
             greater  than ten  percent  (10%),  then the two  appraisers  shall
             within  twenty  (20) days of the date that the later  submittal  is
             submitted to the parties  designate a third appraiser who must also
             be a qualified M.A.I.  appraiser.  The sole  responsibility  of the
             third  appraiser will be to determine  which of the  determinations
             made by the first appraisers is most accurate.  The third appraiser
             shall have no right to propose a middle ground or any  modification
             of either of the  determinations  made by the first two appraisers.
             The third  appraiser's  choice  shall be  submitted  to the parties
             within  thirty  (30)  days  after  his  or  her   selection.   Such
             determination  shall bind both of the parties  and shall  establish
             the Fair Market Rental Value of the Premises.  Each party shall pay
             for their own  appraiser  and shall pay an equal  share of the fees
             and expenses of the third appraiser.


                                       8


             Fair Market  Rental  Value for purpose of this Lease shall mean the
             then prevailing rent for premises comparable in size, quality,  and
             orientation   to  the  demised   Premises,   located  in  buildings
             comparable in size to, and in the general vicinity of, the building
             which the demised Premises are located,  leased on terms comparable
             to the terms contained in this Lease.

8.     RIGHT OF FIRST  OPPORTUNITY  TO LEASE  ADDITIONAL  PREMISES  AT 100 SMITH
       RANCH ROAD, SAN RAFAEL

       At any time during the term hereof, or any options to extend which Tenant
       has exercised,  provided that Tenant is not in default as defined herein,
       Tenant  shall have a right of First  Opportunity  to Lease for all office
       space that  becomes  available  for lease at 100 Smith  Ranch  Road,  San
       Rafael, based on the terms and conditions as outlined below.

       Landlord and Tenant  acknowledge  that there are existing  tenants at 100
       Smith Ranch Road,  which  tenants  have options to renew or wish to renew
       their respective  leases, and that these existing options and requests to
       renew would take precedent  over the Right of First  Opportunity to Lease
       described herein.

       Landlord  and  Tenant  further  acknowledge  that  this  Right  of  First
       Opportunity  to Lease shall apply only to premises,  from which  existing
       tenants vacate or which is currently vacant.

       Landlord shall notify Tenant in writing of the availability of additional
       office  premises at 100 Smith Ranch Road,  San Rafael  within thirty (30)
       days of Landlord  receiving  notice from an existing  Tenant at 100 Smith
       Ranch Road of that Tenant's intent to vacate their  premises.  Landlord's
       notice to Tenant shall include the size of premises,  the projected  date
       at which the premises may be available,  and a floor plan  indicating the
       current configuration of the premises.

       Tenant shall have ten (10) days after  receipt of notice from Landlord to
       notify  Landlord of Tenant's  intent to lease the premises  which was the
       subject of the notice. In the event Landlord does not receive notice from
       Tenant of Tenant's intent to lease said available  space,  Landlord shall
       have the right to lease said  space to any other  Tenant  which  Landlord
       chooses,  and Tenant's Right of First  Opportunity to lease that specific
       premises shall be deemed waived.

       In the  event  Tenant  notifies  Landlord  of its  intent  to lease  said
       premises,  Landlord  and Tenant  shall  proceed as soon as is  reasonably
       possible to execute a lease  agreement  for the  specific  premises  that
       became available. Terms and conditions of the Lease shall be based on the
       same terms and  conditions  of the  lease(s)  on the other  space  Tenant
       occupies in the Building at the time the lease is executed.  Landlord and
       Tenant shall make a good faith effort to execute a Lease for the specific
       available  space  within  thirty  (30) days  after  Tenant  has  notified
       Landlord of its intent to lease said space.

       This  Right  of First  Opportunity  to Lease  shall in no way  limit  the
       Landlord from executing  leases with new tenants for terms of any length,
       with  options to renew for any length,  for those spaces for which Tenant
       has not  exercised  its Right of First  Opportunity  to lease as  defined
       herein.



                                       9


9.     SERVICES AND UTILITIES

       A.    Provided that Tenant is not in default  hereunder,  Landlord agrees
             to furnish to the Premises  five-day per week  janitorial  service.
             Landlord  shall  also  maintain  and keep  lighted,  heated and air
             conditioned   during  reasonable  hours  of  generally   recognized
             business days, the common entries, common corridors,  common stairs
             and toilet  rooms in the  building  of which  Premises  are a part.
             Landlord  shall not be liable for, and Tenant shall not be entitled
             to,  any  reduction  of rental by reason of  Landlord's  failure to
             furnish  any of the  foregoing  when  such  failure  is  caused  by
             accident,  breakage,  repairs,  strikes,  lockouts  or other  labor
             disturbances  or labor disputes of any  character,  or by any other
             cause,  similar or  dissimilar,  beyond the  reasonable  control of
             Landlord.  Landlord shall not be liable under any circumstances for
             a loss of or injury to property,  however occurring,  through or in
             connection  with or  incidental  to failure  to furnish  any of the
             foregoing.

       B.    Tenant shall have 24-hour per day, seven-day per week access to its
             Premises.

       C.    Landlord  shall  provide  Tenant a monthly  allowance  of $3,878.71
             (35,261 rentable SF x $.11) for Tenant's electrical  service.  This
             allowance  is  included in the Base Rent as defined in Article 5 of
             the Lease.

             Landlord and Tenant  recognize  that  Tenant's  electrical  service
             shall  cost in  excess  of $.11 per  square  foot per  month due to
             Tenant's heavy electrical and air conditioning requirements.

             Tenant shall be charged for all PG&E  charges to the building  over
             and  above  the  monthly   allowance   provided  above,   less  any
             over-standard  charges to other tenant's in the building (any usage
             over the $.11  allowance  provided to each  Tenant.) At the time of
             Lease  execution,  no per square foot tenants in the Building other
             than Fireman's Fund who currently occupies the entire second floor,
             have any over-standard  useage.  Landlord shall notify Tenant as to
             any  changes  in the  existing  tenant's  electrical  useage or any
             over-standard useage of new tenants to the building.  Tenant may at
             any time notify Landlord that in Tenant's view, a particular tenant
             may be using over-standard electrical and Landlord will investigate
             that useage with the assistance of an electrical engineer and shall
             report to Tenant its findings regarding the useage and shall charge
             the other tenant for any actual over-standard  useage, which amount
             shall be deducted from Tenant's  over-standard  charges.  If Tenant
             does not agree with Landlord or Landlord's engineer's  calculation,
             Tenant  may have  its own  engineer  evaluate  the  other  tenant's
             useage.

             For the first year of Tenant's  occupancy,  Landlord  shall  charge
             Tenant  $.11 per useable  square  foot per month for  over-standard
             electrical  useage  as a  projected  expense,  which  amount  is an
             average paid by Tenant in its other  Premises  located at 111 Smith
             Ranch Road and 120 North  Redwood  Drive.  This amount  ($3,645.40)
             shall be paid along with the monthly  rent. At the end of the first
             year of occupancy,  Landlord shall prepare a PG&E invoice  analysis
             showing the actual cost of over-standard useage by Tenant. Landlord
             shall  credit  Tenant for any amounts  paid in excess of the actual
             cost of  over-standard  useage.  Tenant  shall pay Landlord for any
             costs in excess of the total  projected sum paid by Tenant over the
             first  year  of   occupancy.   The   amount   paid  by  Tenant  for
             over-standard   electrical  useage  for  each  subsequent  year  of
             occupancy  shall be  based on 


                                       10


             the  previous  year's  charges  and a  similar  accounting  between
             Landlord and Tenant will occur annually.

       D.    The hours of operation of the heating and air  conditioning  system
             for the building are as follows:

                        Monday thru Friday:          7:00 a.m. to 6:00 p.m.
                        Saturdays:                   8:00 a.m. to 3:00 p.m.

       E.    In the event Tenant  requires the  operation of the heating and air
             conditioning  system  beyond the normal hours of operation  for the
             building,  Tenant shall  notify the building  manager in advance of
             the required  extended hour usage,  and the building  manager shall
             program the heating and air  conditioning  system to operate during
             the time period requested by Tenant.

       F.    In the event  Tenant shall  request  that an override  mechanism be
             installed during the term of the Lease, an override mechanism shall
             be  installed  on the heating  and air  conditioning  system  which
             services  Tenant's  premises.  The cost of this mechanism  shall be
             paid by the Tenant at the time of the installation.  This mechanism
             shall  allow  Tenant  to  have  control  of  the  heating  and  air
             conditioning system for its premises in hours other than the normal
             building hours stated above.

             Along  with  the  override  mechanism,  an  hourly  meter  shall be
             attached to the override mechanism which shall measure Tenant's use
             of the  heating  and air  conditioning  system  beyond  the  normal
             building  hours.  On a monthly basis,  Landlord shall charge Tenant
             for this usage by  multiplying  the number of hours used by the per
             hour charge for operating the heating and air  conditioning  system
             which shall be  determined by  Landlord's  electrical  engineer and
             heating and air conditioning contractor.

10.    COMMUNICATIONS INSTALLATION

       Tenant has installed certain communications  equipment on the roof of the
       Building.

       Prior to the end of the term of this Lease, Tenant, at Tenant's sole cost
       and  expense,  shall  remove  the  communications  equipment  and  shall,
       forthwith and with all due  diligence,  repair any damage to the Premises
       caused by such removal.





                                       11



11.    CONSENT

       Landlord  and Tenant  agree that in the event  their  consent is required
       pursuant  to the  provisions  of the  Lease,  such  consent  shall not be
       unreasonably withheld.


         LANDLORD                   THE JOSEPH AND EDA PELL REVOCABLE TRUST



                                    By:    Joseph Pell
                                           -------------------------------------
                                           Joseph Pell

                                    Its:
                                           -------------------------------------


                                    By:    Eda Pell
                                           -------------------------------------
                                           Eda Pell

                                    Its:
                                           -------------------------------------


                                    Date:  March 30, 1994
                                           -------------------------------------




         TENANT                     FAIR, ISAAC AND COMPANY, INCORPORATED



                                    By:    Robert D. Sanderson
                                           -------------------------------------


                                    Its:   Executive Vice President
                                           -------------------------------------


                                    Date:  March 10, 1994
                                           -------------------------------------