[ Arithmetic | The ECLiPSe Built-In Predicates | Reference Manual | Alphabetic Index ]

# /(+Number1, +Number2, -Result)

Evaluates the quotient Number1 / Number2 and unifies the resulting value with Result.

Number1
  A number.
Number2
  A number.
Result
  A variable or float (resp. rational).

## Description

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 type of the division depends on the value of the global flag prefer_rationals. When it is off, the result is a float, when it is on, the result is a rational. In coroutining mode, if Number1 or Number2 are uninstantiated, the call to //3 is delayed until these variables are instantiated.

### Modes and Determinism

- /(+, +, -) is det

### Exceptions

(4) instantiation fault
  Number1 or Number2 is not instantiated (non-coroutining mode only).
(5) type error
  Result is a number but not a float (resp. rational).
(24) number expected
  Number1 or Number2 is not of a numeric type.
(24) number expected
  Result is neither a number nor a variable.
(20) arithmetic exception
  Illegal arithmetic operation: division by 0

## Examples

    Success:
        /(10, 2, 5.0).
        /(10, -2.0, -5.0).
        /(9, 12, 3_4).      (with set_flag(prefer_rationals, on))
    Fail:
        /(1, 2, 1.0).
    Error:
        /(A, 2, 6.0).            (Error 4).
        /(5, 2, r).              (Error 5).
        /(6, 2, 3).              (Error 5).
        /(2, 0, Result).         (Error 20).
        /(4 + 2, 2, 12).         (Error 24).

## See Also

is / 2, get_flag / 2, set_flag / 2