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_______________________________________________________________ *)
17 module E = BrgEnvironment
18 module S = BrgSubstitution
20 exception LRefNotFound of B.message
24 s: (B.term * int) list
27 (* Internal functions *******************************************************)
29 let reductions = ref O.initial_reductions
33 let error i = raise (LRefNotFound (L.items1 (string_of_int i)))
36 let sc, st = s ^ " in the context", "the term" in
37 L.log O.specs level (L.ct_items1 sc c st t)
40 let sc, su, st = s ^ " in the context", "the term", "and the term" in
41 L.log O.specs level (L.ct_items2 sc c su u st t)
44 c = B.empty_context; s = []
49 | Some (_, b) -> f e b
52 let f c = B.get f c i in
56 let map f (v, i) = f (v, succ i) in
59 let unwind_to_term f m t =
60 let map f t (a, b) = f (B.Bind (a, b, t)) in
61 let f mc = C.list_fold_left f map t mc in
67 f {m with c = (a, b) :: m.c}
70 let rec step f ?(delta=false) ?(sty=false) c m x =
71 (* L.warn "entering R.step"; *)
76 | _, _, B.Abbr v when delta ->
77 reductions := O.add ~gdelta:1 !reductions;
78 step f ~delta ~sty c m v
79 | _, _, B.Abst w when sty ->
80 step f ~delta ~sty c m w
82 f m (B.GRef (B.Entry (e, b) :: a, uri))
88 reductions := O.add ~ldelta:1 !reductions;
89 step f ~delta ~sty c m v
90 | B.Abst w when sty ->
91 step f ~delta ~sty c m w
93 f m (B.LRef (B.Entry (e, b) :: a, i))
95 let f e = S.lift_bind (f e) (succ i) (0) in
98 reductions := O.add ~tau:1 !reductions;
99 step f ~delta ~sty c m t
100 | B.Appl (_, v, t) ->
101 step f ~delta ~sty c {m with s = (v, 0) :: m.s} t
102 | B.Bind (a, B.Abst w, t) ->
106 reductions := O.add ~beta:1 !reductions;
107 let f mc = step f ~delta ~sty c {c = mc; s = tl} t in
108 let f v = B.push f m.c a (B.Abbr (B.Cast ([], w, v))) in
111 | B.Bind (a, b, t) ->
112 reductions := O.add ~upsilon:(List.length m.s) !reductions;
113 let f sc mc = step f ~delta ~sty c {c = mc; s = sc} t in
114 let f sc = B.push (f sc) m.c a b in
117 (* Interface functions ******************************************************)
120 let f r = L.unbox level; f r in
122 | B.Bind (_, B.Abst w, _) ->
123 let f w = f (Some w) in unwind_to_term f m w
126 L.box level; log1 "Now scanning" c t;
127 step f ~delta:true ~sty:true c empty_machine t
129 let rec ac_nfs f ~si r c m1 u m2 t =
130 (* L.warn "entering R.are_convertible_aux"; *)
131 log2 "Now converting nfs" c u t;
133 | B.Sort (_, h1), B.Sort (_, h2) ->
134 if h1 = h2 then f r else f false
135 | B.LRef (B.Entry (e1, B.Abst _) :: _, _),
136 B.LRef (B.Entry (e2, B.Abst _) :: _, _) ->
137 if e1 = e2 then ac_stacks f ~si r c m1 m2 else f false
138 | B.GRef (B.Entry (e1, B.Abst _) :: _, _),
139 B.GRef (B.Entry (e2, B.Abst _) :: _, _) ->
140 if e1 = e2 then ac_stacks f ~si r c m1 m2 else f false
141 | B.GRef (B.Entry (e1, B.Abbr v1) :: _, _),
142 B.GRef (B.Entry (e2, B.Abbr v2) :: _, _) ->
147 reductions := O.add ~gdelta:2 !reductions;
148 ac f ~si true c m1 v1 m2 v2
151 ac_stacks f ~si r c m1 m2
152 else if e1 < e2 then begin
153 reductions := O.add ~gdelta:1 !reductions;
154 step (ac_nfs f ~si r c m1 u) c m2 v2
156 reductions := O.add ~gdelta:1 !reductions;
157 step (ac_nfs_rev f ~si r c m2 t) c m1 v1
159 | _, B.GRef (B.Entry (_, B.Abbr v2) :: _, _) ->
160 reductions := O.add ~gdelta:1 !reductions;
161 step (ac_nfs f ~si r c m1 u) c m2 v2
162 | B.GRef (B.Entry (_, B.Abbr v1) :: _, _), _ ->
163 reductions := O.add ~gdelta:1 !reductions;
164 step (ac_nfs_rev f ~si r c m2 t) c m1 v1
165 | B.Bind (a1, (B.Abst w1 as b1), t1),
166 B.Bind (a2, (B.Abst w2 as b2), t2) ->
167 let g m1 m2 = ac f ~si r c m1 t1 m2 t2 in
168 let g m1 = push (g m1) m2 a2 b2 in
169 let f r = if r then push g m1 a1 b1 else f false in
170 ac f ~si r c m1 w1 m2 w2
171 | B.Sort _, B.Bind (a, b, t) when si ->
172 let f m1 m2 = ac f ~si r c m1 u m2 t in
173 let f m1 = push (f m1) m2 a b in
177 and ac_nfs_rev f ~si r c m2 t m1 u = ac_nfs f ~si r c m1 u m2 t
179 and ac f ~si r c m1 t1 m2 t2 =
180 (* L.warn "entering R.are_convertible"; *)
181 let g m1 t1 = step (ac_nfs f ~si r c m1 t1) c m2 t2 in
182 if r = false then f false else step g c m1 t1
184 and ac_stacks f ~si r c m1 m2 =
185 (* L.warn "entering R.are_convertible_stacks"; *)
186 let mm1, mm2 = {m1 with s = []}, {m2 with s = []} in
187 let map f r (v1, h1) (v2, h2) =
188 let f v1 = S.lift (ac f ~si r c mm1 v1 mm2) h2 (0) v2 in
191 if List.length m1.s <> List.length m2.s then
193 (* L.warn (Printf.sprintf "Different lengths: %u %u"
194 (List.length m1.s) (List.length m2.s)
199 C.list_fold_left2 f map r m1.s m2.s
201 let are_convertible f ?(si=false) c u t =
202 let f b = L.unbox level; f b in
203 L.box level; log2 "Now converting" c u t;
204 ac f ~si true c empty_machine u empty_machine t