LINGO currently offers two financial functions. One computes the present value of an annuity. The other returns the present value of a lump sum.

@FPA( I, N)

Returns the present value of an annuity. That is, a stream of $1 payments per period at an interest rate of I for N periods starting one period from now. I is not a percentage, but a fraction representing the interest rate (e.g., you would use .1 to represent 10%). To get the present value of an annuity stream of $X payments, multiply the result by X.

@FPL( I, N)

Returns the present value of a lump sum of $1 N periods from now if the interest rate is I per period. I is not a percentage, but a fraction representing the interest rate (e.g., you would use .1 to represent 10%). To get the present value of a lump sum of $X, multiply the result by X.