TRS: { a__p(0()) -> 0(), a__p(s(X)) -> mark(X), a__leq(0(), Y) -> true(), a__leq(s(X), 0()) -> false(), a__leq(s(X), s(Y)) -> a__leq(mark(X), mark(Y)), a__if(true(), X, Y) -> mark(X), a__if(false(), X, Y) -> mark(Y), a__diff(X, Y) -> a__if(a__leq(mark(X), mark(Y)), 0(), s(diff(p(X), Y))), mark(p(X)) -> a__p(mark(X)), mark(leq(X1, X2)) -> a__leq(mark(X1), mark(X2)), mark(if(X1, X2, X3)) -> a__if(mark(X1), X2, X3), mark(diff(X1, X2)) -> a__diff(mark(X1), mark(X2)), mark(0()) -> 0(), mark(s(X)) -> s(mark(X)), mark(true()) -> true(), mark(false()) -> false(), a__p(X) -> p(X), a__leq(X1, X2) -> leq(X1, X2), a__if(X1, X2, X3) -> if(X1, X2, X3), a__diff(X1, X2) -> diff(X1, X2)} Fail