MAYBE MAYBE TRS: { active(p(X)) -> p(active(X)), active(p(0())) -> mark(0()), active(p(s(X))) -> mark(X), active(s(X)) -> s(active(X)), active(leq(X1, X2)) -> leq(X1, active(X2)), active(leq(X1, X2)) -> leq(active(X1), X2), active(leq(0(), Y)) -> mark(true()), active(leq(s(X), 0())) -> mark(false()), active(leq(s(X), s(Y))) -> mark(leq(X, Y)), active(if(X1, X2, X3)) -> if(active(X1), X2, X3), active(if(true(), X, Y)) -> mark(X), active(if(false(), X, Y)) -> mark(Y), active(diff(X, Y)) -> mark(if(leq(X, Y), 0(), s(diff(p(X), Y)))), active(diff(X1, X2)) -> diff(X1, active(X2)), active(diff(X1, X2)) -> diff(active(X1), X2), p(mark(X)) -> mark(p(X)), p(ok(X)) -> ok(p(X)), s(mark(X)) -> mark(s(X)), s(ok(X)) -> ok(s(X)), leq(X1, mark(X2)) -> mark(leq(X1, X2)), leq(mark(X1), X2) -> mark(leq(X1, X2)), leq(ok(X1), ok(X2)) -> ok(leq(X1, X2)), if(mark(X1), X2, X3) -> mark(if(X1, X2, X3)), if(ok(X1), ok(X2), ok(X3)) -> ok(if(X1, X2, X3)), diff(X1, mark(X2)) -> mark(diff(X1, X2)), diff(mark(X1), X2) -> mark(diff(X1, X2)), diff(ok(X1), ok(X2)) -> ok(diff(X1, X2)), proper(0()) -> ok(0()), proper(p(X)) -> p(proper(X)), proper(s(X)) -> s(proper(X)), proper(true()) -> ok(true()), proper(leq(X1, X2)) -> leq(proper(X1), proper(X2)), proper(false()) -> ok(false()), proper(if(X1, X2, X3)) -> if(proper(X1), proper(X2), proper(X3)), proper(diff(X1, X2)) -> diff(proper(X1), proper(X2)), top(mark(X)) -> top(proper(X)), top(ok(X)) -> top(active(X)) } DUP: We consider a duplicating system. Trs: { active(p(X)) -> p(active(X)), active(p(0())) -> mark(0()), active(p(s(X))) -> mark(X), active(s(X)) -> s(active(X)), active(leq(X1, X2)) -> leq(X1, active(X2)), active(leq(X1, X2)) -> leq(active(X1), X2), active(leq(0(), Y)) -> mark(true()), active(leq(s(X), 0())) -> mark(false()), active(leq(s(X), s(Y))) -> mark(leq(X, Y)), active(if(X1, X2, X3)) -> if(active(X1), X2, X3), active(if(true(), X, Y)) -> mark(X), active(if(false(), X, Y)) -> mark(Y), active(diff(X, Y)) -> mark(if(leq(X, Y), 0(), s(diff(p(X), Y)))), active(diff(X1, X2)) -> diff(X1, active(X2)), active(diff(X1, X2)) -> diff(active(X1), X2), p(mark(X)) -> mark(p(X)), p(ok(X)) -> ok(p(X)), s(mark(X)) -> mark(s(X)), s(ok(X)) -> ok(s(X)), leq(X1, mark(X2)) -> mark(leq(X1, X2)), leq(mark(X1), X2) -> mark(leq(X1, X2)), leq(ok(X1), ok(X2)) -> ok(leq(X1, X2)), if(mark(X1), X2, X3) -> mark(if(X1, X2, X3)), if(ok(X1), ok(X2), ok(X3)) -> ok(if(X1, X2, X3)), diff(X1, mark(X2)) -> mark(diff(X1, X2)), diff(mark(X1), X2) -> mark(diff(X1, X2)), diff(ok(X1), ok(X2)) -> ok(diff(X1, X2)), proper(0()) -> ok(0()), proper(p(X)) -> p(proper(X)), proper(s(X)) -> s(proper(X)), proper(true()) -> ok(true()), proper(leq(X1, X2)) -> leq(proper(X1), proper(X2)), proper(false()) -> ok(false()), proper(if(X1, X2, X3)) -> if(proper(X1), proper(X2), proper(X3)), proper(diff(X1, X2)) -> diff(proper(X1), proper(X2)), top(mark(X)) -> top(proper(X)), top(ok(X)) -> top(active(X)) } Fail