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abs(+Number, -Result)

Unifies the absolute value of Number with Result.
A number.
Output: a number.


This predicate is used by the ECLiPSe compiler to expand evaluable arithmetic expressions. So the call to abs(Number, Result) is equivalent to
    Result is abs(Number)
which should be preferred for portability.

Result is the absolute value of Number, and of the same type.

In coroutining mode, if Number is uninstantiated, the call to abs/2 is delayed until this variable is instantiated.

Modes and Determinism


(4) instantiation fault
Number is not instantiated (non-coroutining mode only).
(24) number expected
Number is not of a numeric type.


    Result is abs(1).		% gives Result = 1
    Result is abs(-5).		% gives Result = 5
    Result is abs(-6.2).	% gives Result = 6.2

    Result is abs(-0.6__-0.5).	% gives Result = 0.5__0.6
    Result is abs(-0.2__0.1).	% gives Result = 0.0__0.2

See Also

is / 2