record Stack {n m : Level } (a : Set n ) {t : Set m } (si : Set n ) : Set (m Level.⊔ n) where
  field
    stack : si
    stackMethods : StackMethods {n} {m} a {t} si
    pushStack :  a -> (Stack a si -> t) -> t
    pushStack d next = push (stackMethods ) (stack ) d (\s1 -> next (record {stack = s1 ; stackMethods = stackMethods } ))