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*(+Number1, +Number2, -Result)

Evaluates the product Number1 * Number2 and unifies the resulting value with Result.
A number.
A number.
A variable or a number.


This predicate is used by the ECLiPSe compiler to expand evaluable arithmetic expressions. So the call to *(Number1, Number2, Result) is equivalent to
    Result is Number1 * Number2
which should be preferred for portability.

The result is of type breal if any of the arguments is a breal, else float if any of the arguments is a float, else rational if any of the arguments is a rational. Only when both arguments are integers is the result an integer.

In coroutining mode, if Number1 or Number2 are uninstantiated, the call to */3 is delayed until these variables are instantiated.

Modes and Determinism


(4) instantiation fault
Number1 or Number2 is not instantiated (non-coroutining mode only).
(5) type error
Result is of a different type than the evaluation result.
(24) number expected
Number1 or Number2 is not of a numeric type.
(24) number expected
Result is neither a number nor a variable.


      *(5, 2, 10).
      *(5, -2.0, -10.0).
      *(1, 2, 3).
      *(5, 2, 10.0).
      *(5, 2.0, 10).
      *(A, 2, 6).             (Error 4).
      *(1, 2, 3.0).           (Error 5).
      *(4 + 2, 2, 12).        (Error 24).
      *(5, 2, r).             (Error 24).

See Also

is / 2