
+(+Number, -Result)

   Checks if Number is a number and unifies it with Result.



Arguments
   Number              A number.
   Result              Output: a number.

Type
   Arithmetic

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.

   Result is identical to Number.

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




Modes and Determinism
   +(+, -) is det

Exceptions
     4 --- Number is not instantiated (non-coroutining mode only).
    24 --- Number is not of a numeric type.

Examples
   
Success:
    Result is + 1.		% gives Result = 1
    Result is + 5.        	% gives Result = 5
    Result is + -6.2.     	% gives Result = -6.2

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


See Also
   is / 2
