(VAR N X XS Y YS ) (RULES from(X) -> cons(X, from(s(X))) sel(0, cons(X, XS)) -> X sel(s(N), cons(X, XS)) -> sel(N, XS) minus(X, 0) -> 0 minus(s(X), s(Y)) -> minus(X, Y) quot(0, s(Y)) -> 0 quot(s(X), s(Y)) -> s(quot(minus(X, Y), s(Y))) zWquot(XS, nil) -> nil zWquot(nil, XS) -> nil zWquot(cons(X, XS), cons(Y, YS)) -> cons(quot(X, Y), zWquot(XS, YS)) )