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nonground(?Term, -Variable)
Succeeds if Term is not a ground term and binds Variable to one of the
variables inside Term.
- Term
- Prolog term.
- Variable
- A variable.
Description
   Used to test whether Term is not ground i.e. whether it contains at
   least one uninstantiated variable.  The argument Variable is unified with one of
   the variables inside Term, i.e. with one of the responsibles for its
   non-groundness.  When Term contains several variables, it is not
   specified which one will be returned as Variable.  As usual, attributed
   variables are also considered variables.
    This predicate can handle cyclic terms.
Modes and Determinism
- nonground(?, -) is semidet
Fail Conditions
Fails if Term is ground
Examples
Success:
    nonground(Term, V).       % unifies V with Term
    nonground(f(a,B,c), V).   % unifies V with B
    nonground([x,Y|Z], V).    % unifies V with Y or Z
    nonground(s(X{a}), V).    % unifies V with X{a}
Fail:
    nonground(atom, V).
    nonground(likes(man, woman), V).
See Also
nonground / 1, nonground / 3, nonvar / 1, var / 1