(* proof construction *******************************************************)
-let rec need_whd i = function
- | C.ACast (_, t, _) -> need_whd i t
- | C.AProd (_, _, _, t) when i > 0 -> need_whd (pred i) t
- | _ when i > 0 -> true
- | _ -> false
-
let lift k n =
let rec lift_xns k (uri, t) = uri, lift_term k t
and lift_ms k = function