(VAR p x xs y )
(RULES 
        app(app(app(if,true),x),y) -> x
        app(app(app(if,true),x),y) -> y
        app(app(takeWhile,p),nil) -> nil
        app(app(takeWhile,p),app(app(cons,x),xs)) -> app(app(app(if,app(p,x)),app(app(cons,x),app(app(takeWhile,p),xs))),nil)
        app(app(dropWhile,p),nil) -> nil
        app(app(dropWhile,p),app(app(cons,x),xs)) -> app(app(app(if,app(p,x)),app(app(dropWhile,p),xs)),app(app(cons,x),xs))
        
)