+++ /dev/null
-(*
- ||M|| This file is part of HELM, an Hypertextual, Electronic
- ||A|| Library of Mathematics, developed at the Computer Science
- ||T|| Department, University of Bologna, Italy.
- ||I||
- ||T|| HELM is free software; you can redistribute it and/or
- ||A|| modify it under the terms of the GNU General Public License
- \ / version 2 or (at your option) any later version.
- \ / This software is distributed as is, NO WARRANTY.
- V_______________________________________________________________ *)
-
-module U = NUri
-module C = Cps
-module L = Log
-module Y = Entity
-module B = Bag
-module O = BagOutput
-module E = BagEnvironment
-module S = BagSubstitution
-
-type machine = {
- i: int;
- c: B.lenv;
- s: B.term list
-}
-
-type whd_result =
- | Sort_ of int
- | LRef_ of int * B.term option
- | GRef_ of B.entity
- | Bind_ of int * B.id * B.term * B.term
-
-type ho_whd_result =
- | Sort of int
- | Abst of B.term
-
-(* Internal functions *******************************************************)
-
-let term_of_whdr = function
- | Sort_ h -> B.Sort h
- | LRef_ (i, _) -> B.LRef i
- | GRef_ (_, uri, _) -> B.GRef uri
- | Bind_ (l, id, w, t) -> B.bind_abst l id w t
-
-let level = 5
-
-let log1 s c t =
- let sc, st = s ^ " in the environment", "the term" in
- L.log O.specs level (L.et_items1 sc c st t)
-
-let log2 s cu u ct t =
- let s1, s2, s3 = s ^ " in the environment", "the term", "and in the environment" in
- L.log O.specs level (L.et_items2 s1 cu s2 u ~sc2:s3 ~c2:ct s2 t)
-
-let empty_machine = {i = 0; c = B.empty_lenv; s = []}
-
-let inc m = {m with i = succ m.i}
-
-let unwind_to_term f m t =
- let map f t (l, id, b) = f (B.Bind (l, id, b, t)) in
- let f mc = C.list_fold_left f map t mc in
- B.contents f m.c
-
-let unwind_stack f m =
- let map f v = unwind_to_term f m v in
- C.list_map f map m.s
-
-let get f c m i =
- let f = function
- | Some (_, b) -> f b
- | None -> assert false
- in
- let f c = B.get f c i in
- B.append f c m.c
-
-let push msg f c m l id w =
- assert (m.s = []);
- let f w = B.push msg f c l id (B.Abst w) in
- unwind_to_term f m w
-
-(* to share *)
-let rec whd f c m x =
-(* L.warn "entering R.whd"; *)
- match x with
- | B.Sort h -> f m (Sort_ h)
- | B.GRef uri ->
- let f entry = f m (GRef_ entry) in
- E.get_entity f uri
- | B.LRef i ->
- let f = function
- | B.Void -> f m (LRef_ (i, None))
- | B.Abst t -> f m (LRef_ (i, Some t))
- | B.Abbr t -> whd f c m t
- in
- get f c m i
- | B.Cast (_, t) -> whd f c m t
- | B.Appl (v, t) -> whd f c {m with s = v :: m.s} t
- | B.Bind (l, id, B.Abst w, t) ->
- begin match m.s with
- | [] -> f m (Bind_ (l, id, w, t))
- | v :: tl ->
- let nl = B.new_location () in
- let f mc = S.subst (whd f c {m with c = mc; s = tl}) nl l t in
- B.push "!" f m.c nl id (B.Abbr (B.Cast (w, v)))
- end
- | B.Bind (l, id, b, t) ->
- let nl = B.new_location () in
- let f mc = S.subst (whd f c {m with c = mc}) nl l t in
- B.push "!" f m.c nl id b
-
-(* Interface functions ******************************************************)
-
-let rec ho_whd f c m x =
-(* L.warn "entering R.ho_whd"; *)
- let aux m = function
- | Sort_ h -> f (Sort h)
- | Bind_ (_, _, w, _) ->
- let f w = f (Abst w) in unwind_to_term f m w
- | LRef_ (_, Some w) -> ho_whd f c m w
- | GRef_ (_, _, Y.Abst w) -> ho_whd f c m w
- | GRef_ (_, _, Y.Abbr v) -> ho_whd f c m v
- | LRef_ (_, None) -> assert false
- | GRef_ (_, _, Y.Void) -> assert false
- in
- whd aux c m x
-
-let ho_whd f c t =
- let f r = L.unbox level; f r in
- L.box level; log1 "Now scanning" c t;
- ho_whd f c empty_machine t
-
-let rec are_convertible f ~si a c m1 t1 m2 t2 =
-(* L.warn "entering R.are_convertible"; *)
- let rec aux m1 r1 m2 r2 =
-(* L.warn "entering R.are_convertible_aux"; *)
- let u, t = term_of_whdr r1, term_of_whdr r2 in
- log2 "Now really converting" c u c t;
- match r1, r2 with
- | Sort_ h1, Sort_ h2 ->
- if h1 = h2 then f a else f false
- | LRef_ (i1, _), LRef_ (i2, _) ->
- if i1 = i2 then are_convertible_stacks f ~si a c m1 m2 else f false
- | GRef_ ((Y.Apix a1 :: _), _, Y.Abst _),
- GRef_ ((Y.Apix a2 :: _), _, Y.Abst _) ->
- if a1 = a2 then are_convertible_stacks f ~si a c m1 m2 else f false
- | GRef_ ((Y.Apix a1 :: _), _, Y.Abbr v1),
- GRef_ ((Y.Apix a2 :: _), _, Y.Abbr v2) ->
- if a1 = a2 then
- let f a =
- if a then f a else are_convertible f ~si true c m1 v1 m2 v2
- in
- are_convertible_stacks f ~si a c m1 m2
- else
- if a1 < a2 then whd (aux m1 r1) c m2 v2 else
- whd (aux_rev m2 r2) c m1 v1
- | _, GRef_ (_, _, Y.Abbr v2) ->
- whd (aux m1 r1) c m2 v2
- | GRef_ (_, _, Y.Abbr v1), _ ->
- whd (aux_rev m2 r2) c m1 v1
- | Bind_ (l1, id1, w1, t1), Bind_ (l2, id2, w2, t2) ->
- let l = B.new_location () in
- let h c =
- let m1, m2 = inc m1, inc m2 in
- let f t1 = S.subst (are_convertible f ~si a c m1 t1 m2) l l2 t2 in
- S.subst f l l1 t1
- in
- let f r = if r then push "!" h c m1 l id1 w1 else f false in
- are_convertible f ~si a c m1 w1 m2 w2
-(* we detect the AUT-QE reduction rule for type/prop inclusion *)
- | Sort_ _, Bind_ (l2, id2, w2, t2) when si ->
- let m1, m2 = inc m1, inc m2 in
- let f c = are_convertible f ~si a c m1 (term_of_whdr r1) m2 t2 in
- push "nsi" f c m2 l2 id2 w2
- | _ -> f false
- and aux_rev m2 r2 m1 r1 = aux m1 r1 m2 r2 in
- let g m1 r1 = whd (aux m1 r1) c m2 t2 in
- if a = false then f false else whd g c m1 t1
-
-and are_convertible_stacks f ~si a c m1 m2 =
-(* L.warn "entering R.are_convertible_stacks"; *)
- let mm1, mm2 = {m1 with s = []}, {m2 with s = []} in
- let map f a v1 v2 = are_convertible f ~si a c mm1 v1 mm2 v2 in
- if List.length m1.s <> List.length m2.s then
- begin
-(* L.warn (Printf.sprintf "Different lengths: %u %u"
- (List.length m1.s) (List.length m2.s)
- ); *)
- f false
- end
- else
- C.list_fold_left2 f map a m1.s m2.s
-
-let are_convertible f ?(si=false) c u t =
- let f b = L.unbox level; f b in
- L.box level; log2 "Now converting" c u c t;
- are_convertible f ~si true c empty_machine u empty_machine t
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