
meta(?Var)

   Succeeds if Var is an attributed variable.



Arguments
   Var                 Prolog term.

Type
   Type Testing

Description
   Used to test whether Var is an attributed variable.

   CAUTION: this test only detects the presence of any attribute, which is
   usually not what is required. It is more common to check for the presence
   of a particular attribute by using a matching clause of the form:

    has_my_attribute(_{my_attr:Attr}) ?-
    	nonvar(Attr).



Modes and Determinism
   meta(?) is semidet

Fail Conditions
   Fails if Var is not an attributed variable

Examples
   
Success:
      meta(X{a}).
      suspend:(X>0), meta(X).

Fail:
      meta(atom).
      meta(X).





See Also
   free / 1, type_of / 2, var / 1
