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free(?Var)

Succeeds if Var is a free variable, not a metaterm.
?Var
Prolog term.

Description

Used to test whether Var is a free variable. free/1 is like var/1 but does not succeed for metaterms.

Fail Conditions

Fails if Var is instantiated or a metaterm.

Resatisfiable

No.

Examples

Success:
      free(X).
      free(_abc).
      free(_).

Fail:
      free(X{a}).
      suspend:(X>0), free(X).
      var(atom).
      var('Abc').

See Also

nonground / 1, nonvar / 1, meta / 1, type_of / 2, var / 1