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