MAYBE MAYBE TRS: { mark(c(X)) -> active(c(X)), mark(f(X)) -> active(f(mark(X))), mark(g(X)) -> active(g(X)), mark(d(X)) -> active(d(X)), mark(h(X)) -> active(h(mark(X))), c(mark(X)) -> c(X), c(active(X)) -> c(X), f(mark(X)) -> f(X), f(active(X)) -> f(X), g(mark(X)) -> g(X), g(active(X)) -> g(X), active(c(X)) -> mark(d(X)), active(f(f(X))) -> mark(c(f(g(f(X))))), active(h(X)) -> mark(c(d(X))), d(mark(X)) -> d(X), d(active(X)) -> d(X), h(mark(X)) -> h(X), h(active(X)) -> h(X) } DUP: We consider a non-duplicating system. Trs: { mark(c(X)) -> active(c(X)), mark(f(X)) -> active(f(mark(X))), mark(g(X)) -> active(g(X)), mark(d(X)) -> active(d(X)), mark(h(X)) -> active(h(mark(X))), c(mark(X)) -> c(X), c(active(X)) -> c(X), f(mark(X)) -> f(X), f(active(X)) -> f(X), g(mark(X)) -> g(X), g(active(X)) -> g(X), active(c(X)) -> mark(d(X)), active(f(f(X))) -> mark(c(f(g(f(X))))), active(h(X)) -> mark(c(d(X))), d(mark(X)) -> d(X), d(active(X)) -> d(X), h(mark(X)) -> h(X), h(active(X)) -> h(X) } Fail