Syntax: @SLN(C, S, L)
C = cost
S = salvage value
L = allowable life
@SLN returns the straight-line depreciation allowance given cost C, salvage value S, and allowable life L. The function is given by:
Examples:
@SLN(5000, 1500, 15) = 233.333
@SLN(S10, S9, 20) = 5, where S9 = 400 and S10 = 500
@SLN(500, 1000, 12) = error!, must have ``Cost'' >= ``Salvage'' >= 0