%ABS (Absolute Value of Expression)
%ABS(numeric expression)
%ABS returns the absolute value of the numeric expression specified as the parameter. If the value of the numeric expression is non-negative, the value is returned unchanged. If the value is negative, the value returned is the value of the expression but with the negative sign removed.
%ABS may be used either in expressions or as parameters to keywords. When used with keywords, the operand must be a numeric literal, a constant name representing a numeric value, or a built-in function with a numeric value known at compile-time.
For more information, see Arithmetic Operations or Built-in Functions.