ground/1ground(+Term)
Term is currently instantiated to a ground term.
Tests whether X is completely instantiated, i.e. free of
unbound variables. In this context, mutable terms are
treated as nonground, so as to make ground/1 a monotone
predicate.
| ?- ground(9).
yes
| ?- ground(major(tom)).
yes
| ?- ground(a(1,Term,3)).
no
| ?- ground("a").
yes
| ?- ground([1,foo(Term)]).
no