TRS: { a__and(true(), X) -> mark(X), a__and(false(), Y) -> false(), a__if(true(), X, Y) -> mark(X), a__if(false(), X, Y) -> mark(Y), a__add(0(), X) -> mark(X), a__add(s(X), Y) -> s(add(X, Y)), a__first(0(), X) -> nil(), a__first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z)), a__from(X) -> cons(X, from(s(X))), mark(and(X1, X2)) -> a__and(mark(X1), X2), mark(if(X1, X2, X3)) -> a__if(mark(X1), X2, X3), mark(add(X1, X2)) -> a__add(mark(X1), X2), mark(first(X1, X2)) -> a__first(mark(X1), mark(X2)), mark(from(X)) -> a__from(X), mark(true()) -> true(), mark(false()) -> false(), mark(0()) -> 0(), mark(s(X)) -> s(X), mark(nil()) -> nil(), mark(cons(X1, X2)) -> cons(X1, X2), a__and(X1, X2) -> and(X1, X2), a__if(X1, X2, X3) -> if(X1, X2, X3), a__add(X1, X2) -> add(X1, X2), a__first(X1, X2) -> first(X1, X2), a__from(X) -> from(X)} Fail