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 BE = BrgEnvironment
22 module BS = BrgSubstitution
23 module BR = BrgReduction
25 (* Internal functions *******************************************************)
29 let message1 st1 m t1 =
30 L.et_items1 "In the environment" m st1 t1
33 let s = s ^ " the term" in
34 L.log st BR.specs (pred level) (message1 s m t)
36 let error1 err s m t =
39 let message3 m t1 t2 ?mu t3 =
40 let sm, st1, st2 = "In the environment", "the term", "is of type" in
43 let smu, st3 = "but in the environment", "it must be of type" in
44 L.et_items3 sm m st1 t1 st2 t2 ~sc3:smu ~c3:mu st3 t3
46 let st3 = "but it must be of type" in
47 L.et_items3 sm m st1 t1 st2 t2 st3 t3
49 let error3 err m t1 t2 ?mu t3 =
50 err (message3 m t1 t2 ?mu t3)
54 let assert_convertibility err f st m u w v =
55 if BR.are_convertible st m zero u m zero w then f () else
58 let assert_applicability err f st m u w v =
59 match BR.xwhd st m None u with
61 error1 err "not a function type" m u
62 | mu, B.Bind (_, B.Abst (true, n, u), _) ->
63 if !G.cc && not (N.assert_not_zero st n) then error1 err "not a function type" m u else
64 if BR.are_convertible st mu zero u m zero w then f () else
65 error3 err m v w ~mu u
66 | _ -> assert false (**)
68 let rec b_type_of err f st m r =
69 if !G.trace >= level then log1 st "Now checking" m r;
72 let h = H.apply h in f r (B.Sort (a, h))
74 begin match BR.get m i with
76 f r (BS.lift (succ i) (0) w)
77 | B.Abbr (B.Cast (_, w, _)) ->
78 f r (BS.lift (succ i) (0) w)
79 | B.Abbr _ -> assert false
81 error1 err "reference to excluded variable" m r
84 begin match BE.get_entity uri with
85 | _, _, _, E.Abst w -> f r w
86 | _, _, _, E.Abbr (B.Cast (_, w, _)) -> f r w
87 | _, _, _, E.Abbr _ -> assert false
89 error1 err "reference to unknown entry" m r
91 | B.Bind (a, B.Abbr v, t) ->
93 f (S.sh2 v rv t rt r (B.bind_abbr a)) (B.bind_abbr a rv tt)
95 let f rv m = b_type_of err (f rv) st m t in
96 let f rv = f rv (BR.push m a (B.abbr rv)) in
97 let f rv vv = match rv with
99 | _ -> f (B.Cast (E.empty_node, vv, rv))
102 | B.Bind (a, B.Abst (x, n, u), t) ->
104 f (S.sh2 u ru t rt r (B.bind_abst x n a)) (B.bind_abst x (N.minus st n 1) a ru tt)
106 let f ru m = b_type_of err (f ru) st m t in
107 let f ru _ = f ru (BR.push m a (B.abst x n ru)) in
109 | B.Bind (a, B.Void, t) ->
111 f (S.sh1 t rt r (B.bind_void a)) (B.bind_void a tt)
113 b_type_of err f st (BR.push m a B.Void) t
114 | B.Appl (a, v, t) ->
116 let f _ = f (S.sh2 v rv t rt r (B.appl a)) (B.appl a rv tt) in
117 assert_applicability err f st m tt vv rv
119 let f rv vv = b_type_of err (f rv vv) st m t in
121 | B.Cast (a, u, t) ->
123 let f _ = f (S.sh2 u ru t rt r (B.cast a)) ru in
124 assert_convertibility err f st m ru tt rt
126 let f ru _ = b_type_of err (f ru) st m t in
129 (* Interface functions ******************************************************)
131 and type_of err f st m r = b_type_of err f st m r