
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.




Resatisfiable
      No.

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
