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-(+Number, -Result)

Unifies the negative of Number with Result.
Number
A number.
Result
A variable or a number.

Description

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

Number and Result have to be of the same type.

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

Modes and Determinism

Exceptions

(4) instantiation fault
Number is not instantiated (non-coroutining mode only).
(5) type error
Result and Number are numbers of different types.
(24) number expected
Number is not of a numeric type.
(24) number expected
Result is neither a number nor a variable.

Examples

Success:
      -(1, -1).
      -(5, Result).        (gives Result = -5)
      -(-6.2, Result).     (gives Result = 6.2)
Fail:
      -(1, 0).
Error:
      -(A, 6).                   (Error 4).
      -(1, -1.0).                (Error 5).
      -(1.0, -1).                (Error 5).
      -(4 + 2, -6).              (Error 24).
      -(1, r).                   (Error 24).



See Also

is / 2