2 ||M|| This file is part of HELM, an Hypertextual, Electronic
3 ||A|| Library of Mathematics, developed at the Computer Science
4 ||T|| Department, University of Bologna, Italy.
6 ||T|| HELM is free software; you can redistribute it and/or
7 ||A|| modify it under the terms of the GNU General Public License
8 \ / version 2 or (at your option) any later version.
9 \ / This software is distributed as is, NO WARRANTY.
10 V_______________________________________________________________ *)
18 module E = BagEnvironment
19 module S = BagSubstitution
21 exception LRefNotFound of B.message
30 | LRef_ of int * B.term option
32 | Bind_ of int * B.id * B.term * B.term
38 type ac_result = (int * NUri.uri * Bag.term list) list option
40 (* Internal functions *******************************************************)
44 let error i = raise (LRefNotFound (L.items1 (string_of_int i)))
46 let empty_machine = {c = B.empty_context; s = []}
49 let f gl ges = B.contents (f gl ges) m.c in
52 let unwind_to_context f c m = B.append f c m.c
54 let unwind_to_term f m t =
55 let map f t (l, id, b) = f (B.Bind (l, id, b, t)) in
56 let f mc = C.list_fold_left f map t mc in
59 let unwind_stack f m =
60 let map f v = unwind_to_term f m v in
68 let f c = B.get f c i in
69 unwind_to_context f c m
71 let push f c m l id w =
73 let f w = B.push f c l id (B.Abst w) in
77 let rec whd f c m x = match x with
78 | B.Sort h -> f m (Sort_ h)
80 let f obj = f m (GRef_ obj) in
84 | B.Void -> f m (LRef_ (i, None))
85 | B.Abst t -> f m (LRef_ (i, Some t))
86 | B.Abbr t -> whd f c m t
89 | B.Cast (_, t) -> whd f c m t
90 | B.Appl (v, t) -> whd f c {m with s = v :: m.s} t
91 | B.Bind (l, id, B.Abst w, t) ->
93 | [] -> f m (Bind_ (l, id, w, t))
95 let f mc = whd f c {c = mc; s = tl} t in
96 B.push f m.c l id (B.Abbr (B.Cast (w, v)))
98 | B.Bind (l, id, b, t) ->
99 let f mc = whd f c {m with c = mc} t in
102 let insert f i uri vs = function
103 | Some l -> f (Some ((i, uri, vs) :: l))
104 | None -> assert false
106 (* Interface functions ******************************************************)
108 let rec ho_whd f c m x =
110 | Sort_ h -> f c (Sort h)
111 | Bind_ (_, _, w, _) ->
112 let f c = f c (Abst w) in unwind_to_context f c m
113 | LRef_ (_, Some w) -> ho_whd f c m w
114 | GRef_ (_, _, B.Abst u) -> ho_whd f c m u
115 | GRef_ (_, _, B.Abbr t) -> ho_whd f c m t
116 | LRef_ (_, None) -> assert false
117 | GRef_ (_, _, B.Void) -> assert false
122 let f c r = L.unbox level; f c r in
123 L.box level; L.log O.specs level (L.ct_items1 "Now scanning" c t);
124 ho_whd f c empty_machine t
126 let rec are_convertible f xl c m1 t1 m2 t2 =
127 let rec aux m1 r1 m2 r2 = match r1, r2 with
128 | Sort_ h1, Sort_ h2 ->
129 if h1 = h2 then f xl else f None
130 | LRef_ (i1, _), LRef_ (i2, _) ->
131 if i1 = i2 then are_convertible_stacks f xl c m1 m2 else f None
132 | GRef_ (a1, _, B.Abst _), GRef_ (a2, _, B.Abst _) ->
133 if a1 = a2 then are_convertible_stacks f xl c m1 m2 else f None
134 | GRef_ (a1, _, B.Abbr v1), GRef_ (a2, _, B.Abbr v2) ->
135 if a1 = a2 then are_convertible_stacks f xl c m1 m2 else
136 if a1 < a2 then whd (aux m1 r1) c m2 v2 else
137 whd (aux_rev m2 r2) c m1 v1
138 | _, GRef_ (_, _, B.Abbr v2) ->
139 whd (aux m1 r1) c m2 v2
140 | GRef_ (_, _, B.Abbr v1), _ ->
141 whd (aux_rev m2 r2) c m1 v1
142 | Bind_ (l1, id1, w1, t1), Bind_ (l2, id2, w2, t2) ->
144 let h c = S.subst (are_convertible f xl c m1 t1 m2) l1 l2 t2 in
145 if xl = None then f xl else push h c m1 l1 id1 w1
147 are_convertible f xl c m1 w1 m2 w2
148 (* we detect the AUT-QE reduction rule for type/prop inclusion *)
149 | GRef_ (_, uri, B.Abst _), Bind_ (l2, _, _, _) ->
150 let g vs = insert f l2 uri vs xl in
151 if U.eq uri I.imp then unwind_stack g m1 else
152 begin L.warn (U.string_of_uri uri); f None end
154 and aux_rev m2 r2 m1 r1 = aux m1 r1 m2 r2 in
155 let f m1 r1 = whd (aux m1 r1) c m2 t2 in
158 and are_convertible_stacks f xl c m1 m2 =
159 let mm1, mm2 = {m1 with s = []}, {m2 with s = []} in
160 let map f xl v1 v2 = are_convertible f xl c mm1 v1 mm2 v2 in
161 if List.length m1.s <> List.length m2.s then f None else
162 C.list_fold_left2 f map xl m1.s m2.s
164 let are_convertible f c u t =
165 let f b = L.unbox level; f b in
167 L.log O.specs level (L.ct_items2 "Now converting" c u "and" c t);
168 are_convertible f (Some []) c empty_machine u empty_machine t