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# meta(?Var)

Succeeds if Var is an attributed variable.

Var
  Prolog term.

## 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