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