(VAR X XS N 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)) )