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                                                                   EXHIBIT 10.31

                                PROMISSORY NOTE

January 2, 2001

$353,468.50

        FOR VALUE RECEIVED, TODD K. YAMAMI ("BORROWER"), an employee of VERITY,
INC. ("COMPANY"), hereby unconditionally promises to pay to the order of
Company, in lawful money of the United States of America and in immediately
available funds, the principal sum of Three Hundred and Fifty-three Thousand,
Four Hundred and Sixty-eight Dollars and Fifty Cents ($353,468.50) (the "LOAN")
together with accrued and unpaid interest thereon, each due and payable on the
dates and in the manner set forth below.

        It is the intent of the parties that the purpose of this Note is not
for consumer, family or household purposes.

        1.       PRINCIPAL REPAYMENT. The outstanding principal amount of the
Loan shall be due and payable on May 31, 2001 (the "Maturity Date").

        2.      INTEREST RATE. Borrower further promises to pay interest on the
outstanding principal amount hereof from the date hereof until payment in full,
which interest shall be payable at the rate of five and ninety-four
one-hundredths percent (5.94%) per annum or the maximum rate permissible by law
(which under the laws of the State of California shall be deemed to be the laws
relating to permissible rates of interest on commercial loans), whichever is
less, and shall be compounded monthly. Interest shall be due and payable not
later than the Maturity Date and shall be calculated on the basis of a 360 day
year for the actual number of days elapsed.

        3.      PLACE OF PAYMENT. All amounts payable hereunder shall be
payable at the office of Company unless another place of payment shall be
specified in writing by Company.

        4.      APPLICATION OF PAYMENTS. Payment on this Note shall be applied
first to accrued interest, if any, and thereafter to the outstanding principal
balance hereof.

        5.      DEFAULT. Each of the following events shall be an "EVENT OF
DEFAULT" hereunder:

                (a)     Borrower fails to pay timely any of the principal amount
due under this Note on the date the same becomes due and payable or any accrued
interest or other amounts due under this Note on the date the same becomes due
and payable;

                (b)     Borrower files a petition or action for relief under
any bankruptcy, insolvency or moratorium law or any other law for the relief
of, or relating to, debtors, now or hereafter in effect, or makes any
assignment for the benefit of creditors or takes any action in furtherance of
any of the foregoing;


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          (c)  An involuntary petition is filed against Borrower (unless such
petition is dismissed or discharged within sixty (60) days) under any
bankruptcy statute now or hereafter in effect, or a custodian, receiver,
trustee, assignee for the benefit of creditors (or other similar official) is
appointed to take possession, custody or control of any property of Borrower;

          (d)  Borrower's employment with Company is terminated by death of
Borrower.

Upon the occurrence of an Event of Default hereunder, all unpaid principal,
accrued interest and other amounts owing hereunder shall, at the option of
Company, and, in the case of an Event of Default pursuant to (b) or (c) above,
automatically, be immediately due, payable and collectible by Company pursuant
to applicable law. Company shall have all rights and may exercise any remedies
available to it under law, successively or concurrently. Borrower expressly
acknowledges and agrees that Company shall have the right to offset any
obligations of Borrower hereunder against salaries, bonuses or other amounts
that may be payable to Borrower by Company.

     6.  WAIVER. Borrower waives presentment and demand for payment, notice of
dishonor, protest and notice of protest of this Note, and shall pay all costs
of collection when incurred, including, without limitation, reasonable
attorneys' fees, costs and other expenses.

     The right to plead any and all statutes of limitations as a defense to any
demands hereunder is hereby waived to the full extent permitted by law.

     7.  GOVERNING LAW. This Note shall be governed by, and construed and
enforced in accordance with, the laws of the State of California, excluding
conflict of laws principles that would cause the application of laws of any
other jurisdiction.

     8.  SUCCESSORS AND ASSIGNS. The provisions of this Note shall inure to the
benefit of and be binding on any successor to Borrower and shall extend to any
holder hereof. Borrower shall not, without the prior written consent of holder,
assign any of its rights or obligations hereunder.


BORROWER:                                    /s/ TODD K. YAMAMI
                                             -------------------------------
                                             Todd K. Yamami








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