module T = Term
module C = Common

type lvl  = Lvl of int

type closure  = C  of env * T.term
and  closure2 = C2 of env * T.term (* 2 variables missing *)

(* tr , icit, ty *)
and spine = (value * C.icit * value) list

and env = value list

and value
  = Type
  | T0
  | T1
  | T1vl
  | TNat
  | Suc   of value
  | Zero
  | TBool
  | True
  | False
  | Pi    of C.icit * value  * closure
  | Lam   of C.icit * closure
  | Sg    of value  * closure
  | Pair  of value  * value
  | Stuck of stuck  * value (* second arg is type *)

and stuck
  = Var  of lvl
  | Meta of C.meta
  | Ind0 of closure * stuck
  | IndN of closure * value * closure2 * stuck
  | IndB of closure * value * value * stuck
  | App  of stuck * spine (* fn; vals; type of fn *)
  | Fst  of stuck
  | Snd  of stuck