
not +Goal

   Succeeds if Goal cannot be satisfied (uses negation as failure).



Arguments
   Goal                Atom or compound term.

Type
   Control

Description
   Used to fail if Goal succeeds.  Uses the standard Prolog form of
   negation as failure.


   To check whether a call Goal succeeds without binding variables, the
   call not not Goal can be used.  Note that !/0 does not cut through
   not/1.




Modes and Determinism
   not(+) is semidet

Modules
   This predicate is sensitive to its module context (tool predicate, see @/2).

Fail Conditions
   Fails if Goal succeeds

Examples
   
Success:
      not fail .
      not 1 == 2 .
      not X==1 .
      not not X = 1.
          % does not bind X
Fail:
      not(X=1).
      not(true).
      not(3 == 3).





See Also
   \+ / 1, ~ / 1, -> / 2
