ground/1 meta-logicalground(+Term)
Term is currently instantiated to a term that is completely bound (has no uninstantiated variables in it).
| ?- ground(9).
yes
| ?- ground(major(tom)).
yes
| ?- ground(a(1,Term,3)).
no
| ?- ground("a").
yes
| ?- ground([1,foo(Term)]).
no
atom/1,
atomic/1,
number/1,
var/1,
compound/1,
callable/1,
nonvar/1,
simple/1