(VAR F lx x xs y ys )
(RULES 
        app(nil, xs) -> xs
        app(cons(x, xs), ys) -> cons(x, app(xs, ys))
        foldl(F, xs, nil) -> xs
        foldl(F, xs, cons(y, ys)) -> foldl(F, , ys)
        iconsc -> 
        reverse(xs) -> foldl(iconsc, nil, xs)
        reverse1(xs) -> foldl(, nil, xs)
        
)