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_______________________________________________________________ *)
21 module ZE = BagEnvironment
22 module ZS = BagSubstitution
32 | LRef_ of J.mark * Z.term option
34 | Bind_ of Z.attrs * J.mark * Z.term * Z.term
40 (* Internal functions *******************************************************)
44 let term_of_whdr = function
46 | LRef_ (i, _) -> Z.LRef i
47 | GRef_ (_, _, uri, _) -> Z.GRef uri
48 | Bind_ (a, l, w, t) -> Z.bind_abst a l w t
51 let sc, st = s ^ " in the environment", "the term" in
52 L.log ZO.specs level (L.et_items1 sc c st t)
54 let log2 s cu u ct t =
55 let s1, s2, s3 = s ^ " in the environment", "the term", "and in the environment" in
56 L.log ZO.specs level (L.et_items2 s1 cu s2 u ~sc2:s3 ~c2:ct s2 t)
58 let empty_machine = {i = 0; c = Z.empty_lenv; s = []}
60 let inc m = {m with i = succ m.i}
62 let unwind_to_term f m t =
63 let map f t (a, l, b) = f (Z.Bind (a, l, b, t)) in
64 let f mc = C.list_fold_left f map t mc in
67 let unwind_stack f m =
68 let map f v = unwind_to_term f m v in
73 let f c = Z.get C.err f c i in
76 let push msg f c m a l w =
78 let f w = Z.push msg f c a l (Z.Abst w) in
83 (* L.warn "entering R.whd"; *)
85 | Z.Sort h -> f m (Sort_ h)
87 let f entry = f m (GRef_ entry) in
91 | Z.Void -> f m (LRef_ (i, None))
92 | Z.Abst t -> f m (LRef_ (i, Some t))
93 | Z.Abbr t -> whd f c m t
96 | Z.Cast (_, t) -> whd f c m t
97 | Z.Appl (v, t) -> whd f c {m with s = v :: m.s} t
98 | Z.Bind (a, l, Z.Abst w, t) ->
100 | [] -> f m (Bind_ (a, l, w, t))
102 let nl = J.new_mark () in
103 let f mc = ZS.subst (whd f c {m with c = mc; s = tl}) nl l t in
104 Z.push "!" f m.c a nl (Z.Abbr (Z.Cast (w, v)))
106 | Z.Bind (a, l, b, t) ->
107 let nl = J.new_mark () in
108 let f mc = ZS.subst (whd f c {m with c = mc}) nl l t in
109 Z.push "!" f m.c a nl b
111 (* Interface functions ******************************************************)
113 let rec ho_whd f c m x =
114 (* L.warn "entering R.ho_whd"; *)
116 | Sort_ h -> f (Sort h)
117 | Bind_ (_, _, w, _) ->
118 let f w = f (Abst w) in unwind_to_term f m w
119 | LRef_ (_, Some w) -> ho_whd f c m w
120 | GRef_ (_, _, _, E.Abst w) -> ho_whd f c m w
121 | GRef_ (_, _, _, E.Abbr v) -> ho_whd f c m v
122 | LRef_ (_, None) -> assert false
123 | GRef_ (_, _, _, E.Void) -> assert false
127 let ho_whd f st c t =
128 if !G.trace >= level then log1 "Now scanning" c t;
129 ho_whd f c empty_machine t
131 let rec are_convertible f st a c m1 t1 m2 t2 =
132 (* L.warn "entering R.are_convertible"; *)
133 let rec aux m1 r1 m2 r2 =
134 (* L.warn "entering R.are_convertible_aux"; *)
135 let u, t = term_of_whdr r1, term_of_whdr r2 in
136 if !G.trace >= level then log2 "Now really converting" c u c t;
138 | Sort_ h1, Sort_ h2 ->
139 if h1 = h2 then f a else f false
140 | LRef_ (i1, _), LRef_ (i2, _) ->
141 if i1 = i2 then are_convertible_stacks f st a c m1 m2 else f false
142 | GRef_ (_, {E.n_apix = Some a1}, _, E.Abst _),
143 GRef_ (_, {E.n_apix = Some a2}, _, E.Abst _) ->
144 if a1 = a2 then are_convertible_stacks f st a c m1 m2 else f false
145 | GRef_ (_, {E.n_apix = Some a1}, _, E.Abbr v1),
146 GRef_ (_, {E.n_apix = Some a2}, _, E.Abbr v2) ->
149 if a then f a else are_convertible f st true c m1 v1 m2 v2
151 are_convertible_stacks f st a c m1 m2
153 if a1 < a2 then whd (aux m1 r1) c m2 v2 else
154 whd (aux_rev m2 r2) c m1 v1
155 | _, GRef_ (_, _, _, E.Abbr v2) ->
156 whd (aux m1 r1) c m2 v2
157 | GRef_ (_, _, _, E.Abbr v1), _ ->
158 whd (aux_rev m2 r2) c m1 v1
159 | Bind_ (a1, l1, w1, t1), Bind_ (a2, l2, w2, t2) ->
160 let l = J.new_mark () in
162 let m1, m2 = inc m1, inc m2 in
163 let f t1 = ZS.subst (are_convertible f st a c m1 t1 m2) l l2 t2 in
166 let f r = if r then push "!" h c m1 a1 l w1 else f false in
167 are_convertible f st a c m1 w1 m2 w2
168 (* we detect the AUT-QE reduction rule for type/prop inclusion *)
169 | Sort_ _, Bind_ (a2, l2, w2, t2) when st.S.si ->
170 let m1, m2 = inc m1, inc m2 in
171 let f c = are_convertible f st a c m1 (term_of_whdr r1) m2 t2 in
172 push "nsi" f c m2 a2 l2 w2
174 and aux_rev m2 r2 m1 r1 = aux m1 r1 m2 r2 in
175 let g m1 r1 = whd (aux m1 r1) c m2 t2 in
176 if a = false then f false else whd g c m1 t1
178 and are_convertible_stacks f st a c m1 m2 =
179 (* L.warn "entering R.are_convertible_stacks"; *)
180 let mm1, mm2 = {m1 with s = []}, {m2 with s = []} in
181 let map f a v1 v2 = are_convertible f st a c mm1 v1 mm2 v2 in
182 if List.length m1.s <> List.length m2.s then
184 (* L.warn (Printf.sprintf "Different lengths: %u %u"
185 (List.length m1.s) (List.length m2.s)
190 C.list_fold_left2 f map a m1.s m2.s
192 let are_convertible f st c u t =
193 if !G.trace >= level then log2 "Now converting" c u c t;
194 are_convertible f st true c empty_machine u empty_machine t