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

number(?Number)

Succeeds if Number is a number.
Number
Prolog term.

Description

Used to test whether Number is a number. number/1 could be defined as

   number(X) :- integer(X).
   number(X) :- rational(X).
   number(X) :- float(X).
   number(X) :- breal(X).

Modes and Determinism

Fail Conditions

Fails if Number is not a number

Examples

   Success:
   number(10).
   number(-21.0).
   number(1_3).
   number(3e27).
   Fail:
   number(pi).
   number(e).
   number('-21.0').
   number(X).
   number(fred).



See Also

atomic / 1, integer / 1, breal / 1, rational / 1, float / 1, real / 1