PLOGHELP TRUE                                 Chris Mellish, August 1982
                                Revised by Kathryn Seifert  October 1986

Predicate which always succeeds as a goal

    ?- true.

Keywords: goal, goal satisfaction, success

-- RELATED DOCUMENTATION ----------------------------------------------

PLOGHELP * REPEAT
 Predicate which succeeds infinitely many times on backtracking

PLOGHELP * FAIL
 A predicate which always fails when called as a goal