Subtract

See Also: Add, Decrement, Increment, Move

Purpose

To perform subtraction.

Syntax

subtract
    value
from
    variable

What It Does

The subtract command subtracts value from variable. Value can be a constant, a number, or an expression.

The following two lines of code are equivalent:

Move (invoice.amount - vendor.total_due) to vendor.total_due
Subtract invoice.amount from vendor.total_due

The subtract and add commands are often used in the data-dictionary procedures Update and Backout as follows:

Procedure Update
    Forward Send Update
    Add invoice.amount to vendor.total_due
End_Procedure

Procedure Backout
    Forward Send Backout
    Subtract invoice.amount from vendor.total_due
End_Procedure