(VAR x xs ys )
(STRATEGY INNERMOST)
(RULES 
        shuffle(Cons(x,xs)) -> Cons(x,shuffle(reverse(xs)))
        reverse(Cons(x,xs)) -> append(reverse(xs),Cons(x,Nil))
        append(Cons(x,xs),ys) -> Cons(x,append(xs,ys))
        shuffle(Nil) -> Nil
        reverse(Nil) -> Nil
        append(Nil,ys) -> ys
        goal(xs) -> shuffle(xs)
        
)