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_______________________________________________________________ *)
24 module BE = BrgEnvironment
27 e: B.lenv; (* environment *)
28 s: (B.lenv * B.term) list; (* stack *)
30 d: int; (* inferred type iterations *)
31 n: int option; (* expected type iterations *)
34 type message = (kam, B.term) L.message
36 (* Internal functions *******************************************************)
41 let sc, st = s ^ " in the environment", "the term" in
42 L.log BO.specs level (L.et_items1 sc c st t)
44 let log2 s cu u ct t =
45 let s1, s2, s3 = s ^ " in the environment (expected)", "the term", "and in the environment (inferred)" in
46 L.log BO.specs level (L.et_items2 s1 cu s2 u ~sc2:s3 ~c2:ct s2 t)
48 let rec list_and map = function
49 | hd1 :: tl1, hd2 :: tl2 ->
50 if map hd1 hd2 then list_and map (tl1, tl2) else false
56 let are_alpha_convertible err f t1 t2 =
57 let rec aux f = function
58 | B.Sort (_, p1), B.Sort (_, p2)
59 | B.LRef (_, p1), B.LRef (_, p2) ->
60 if p1 = p2 then f () else err ()
61 | B.GRef (_, u1), B.GRef (_, u2) ->
62 if U.eq u1 u2 then f () else err ()
63 | B.Cast (_, v1, t1), B.Cast (_, v2, t2)
64 | B.Appl (_, v1, t1), B.Appl (_, v2, t2) ->
65 let f _ = aux f (t1, t2) in
67 | B.Bind (_, b1, t1), B.Bind (_, b2, t2) ->
68 let f _ = aux f (t1, t2) in
71 and aux_bind f = function
72 | B.Abbr v1, B.Abbr v2 -> aux f (v1, v2)
73 | B.Abst (n1, v1), B.Abst (n2, v2) when n1 = n2 -> aux f (v1, v2)
74 | B.Void, B.Void -> f ()
77 if W.eq t1 t2 then f () else aux f (t1, t2)
79 let assert_tstep m vo = match m.n with
83 let tstep m = {m with d = succ m.d}
86 let _, c, a, b = B.get m.e i in c, a, b
90 log1 (Printf.sprintf "entering R.step: l:%u d:%i n:%s" m.l m.d (match m.n with Some n -> string_of_int n | None -> "infinite")) m.e x;
93 if assert_tstep m false then
94 step st (tstep m) (B.Sort (a, H.apply h))
97 begin match BE.get_entity uri with
98 | _, _, E.Abbr v when st.S.delta ->
99 O.add ~gdelta:1 (); step st m v
100 | _, _, E.Abst (_, w) when assert_tstep m true ->
101 O.add ~grt:1 (); step st (tstep m) w
110 begin match get m i with
113 step st {m with e = c} v
114 | c, _, B.Abst (_, w) when assert_tstep m true ->
116 step st {(tstep m) with e = c} w
118 m, B.LRef (a, i), None
122 | B.Cast (_, u, t) ->
123 if assert_tstep m false then begin
130 | B.Appl (_, v, t) ->
131 step st {m with s = (m.e, v) :: m.s} t
132 | B.Bind (a, B.Abst (n, w), t) ->
133 let n = N.minus n m.d in
134 let x = B.Bind (a, B.Abst (n, w), t) in
138 if N.is_zero n then Q.add_nonzero st.S.cc a;
139 O.add ~beta:1 ~theta:(List.length s) ();
140 let e = B.push m.e c a (B.abbr v) (* (B.Cast ([], w, v)) *) in
141 step st {m with e = e; s = s} t
143 | B.Bind (a, b, t) ->
144 O.add ~theta:(List.length m.s) ();
145 let e = B.push m.e m.e a b in
146 step st {m with e = e} t
148 let reset m ?(e=m.e) n =
149 {m with e = e; n = n; s = []; d = 0}
151 let assert_iterations m1 m2 = match m1.n, m2.n with
152 | Some n1, Some n2 -> n1 - m1.d = n2 - m2.d
157 let a, l = match b with
158 | B.Abst _ -> E.Apix m.l :: a, succ m.l
161 let e = B.push m.e m.e a b in
162 {m with e = e; l = l}
164 let rec ac_nfs st (m1, t1, r1) (m2, t2, r2) =
165 log2 "Now converting nfs" m1.e t1 m2.e t2;
166 match t1, r1, t2, r2 with
167 | B.Sort (_, h1), _, B.Sort (_, h2), _ ->
169 | B.LRef (a1, _), _, B.LRef (a2, _), _ ->
170 let e1 = E.apix C.err C.start a1 in
171 let e2 = E.apix C.err C.start a2 in
172 if e1 = e2 then ac_stacks st m1 m2 else false
173 | B.GRef (_, u1), None, B.GRef (_, u2), None ->
174 if U.eq u1 u2 & assert_iterations m1 m2 then ac_stacks st m1 m2 else false
175 | B.GRef (a1, u1), Some v1, B.GRef (a2, u2), Some v2 ->
176 let e1 = E.apix C.err C.start a1 in
177 let e2 = E.apix C.err C.start a2 in
178 if e1 < e2 then begin
180 ac_nfs st (m1, t1, r1) (step st m2 v2)
181 end else if e2 < e1 then begin
183 ac_nfs st (step st m1 v1) (m2, t2, r2)
184 end else if U.eq u1 u2 & assert_iterations m1 m2 && ac_stacks st m1 m2 then true
189 | _, _, B.GRef _, Some v2 ->
191 ac_nfs st (m1, t1, r1) (step st m2 v2)
192 | B.GRef _, Some v1, _, _ ->
194 ac_nfs st (step st m1 v1) (m2, t2, r2)
195 | B.Bind (a1, (B.Abst (n1, w1) as b1), t1), _,
196 B.Bind (a2, (B.Abst (n2, w2) as b2), t2), _ ->
197 if n1 = n2 then () else Q.add_equal st.S.cc a1 a2;
198 if ac {st with S.si = false} (reset m1 zero) w1 (reset m2 zero) w2 then
199 ac st (push m1 a1 b1) t1 (push m2 a2 b2) t2
201 | B.Sort _, _, B.Bind (a, (B.Abst (n, _) as b), t), _ ->
202 if N.is_zero n then () else Q.add_zero st.S.cc a;
204 ac st (push m1 a b) t1 (push m2 a b) t
207 and ac st m1 t1 m2 t2 =
208 (* L.warn "entering R.are_convertible"; *)
209 ac_nfs st (step st m1 t1) (step st m2 t2)
211 and ac_stacks st m1 m2 =
212 (* L.warn "entering R.are_convertible_stacks"; *)
213 if List.length m1.s <> List.length m2.s then false else
214 let map (c1, v1) (c2, v2) =
215 let m1, m2 = reset m1 ~e:c1 zero, reset m2 ~e:c2 zero in
216 ac {st with S.si = false} m1 v1 m2 v2
218 list_and map (m1.s, m2.s)
220 (* Interface functions ******************************************************)
223 e = B.empty; s = []; l = 0; d = 0; n = None
228 let _, _, _, b = B.get m.e i in b
231 L.box level; log1 "Now scanning" m.e t;
232 let m, t, _ = step {st with S.delta = true} (reset m n) t in
235 let are_convertible st m1 n1 t1 m2 n2 t2 =
236 L.box level; log2 "Now converting" m1.e t1 m2.e t2;
237 let r = ac {st with S.delta = st.S.expand} (reset m1 n1) t1 (reset m2 n2) t2 in
240 if W.eq mu mw then are_alpha_convertible err f u w else err () *)
242 (* error reporting **********************************************************)
244 let pp_term m frm t = BO.specs.L.pp_term m.e frm t
246 let pp_lenv frm m = BO.specs.L.pp_lenv frm m.e
249 L.pp_term = pp_term; L.pp_lenv = pp_lenv