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 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 (_, u), _) ->
63 if BR.are_convertible st mu zero u m zero w then f () else
64 error3 err m v w ~mu u
65 | _ -> assert false (**)
67 let rec b_type_of err f st m x =
68 if !G.trace >= level then log1 st "Now checking" m x;
71 let h = H.apply h in f x (B.Sort (a, h))
73 begin match BR.get m i with
75 f x (BS.lift (succ i) (0) w)
76 | B.Abbr (B.Cast (_, w, _)) ->
77 f x (BS.lift (succ i) (0) w)
78 | B.Abbr _ -> assert false
80 error1 err "reference to excluded variable" m x
83 begin match BE.get_entity uri with
84 | _, _, _, E.Abst w -> f x w
85 | _, _, _, E.Abbr (B.Cast (_, w, _)) -> f x w
86 | _, _, _, E.Abbr _ -> assert false
88 error1 err "reference to unknown entry" m x
90 | B.Bind (a, B.Abbr v, t) ->
92 f (S.sh2 v xv t xt x (B.bind_abbr a)) (B.bind_abbr a xv tt)
94 let f xv m = b_type_of err (f xv) st m t in
95 let f xv = f xv (BR.push m a (B.abbr xv)) in
96 let f xv vv = match xv with
98 | _ -> f (B.Cast (E.empty_node, vv, xv))
101 | B.Bind (a, B.Abst (n, u), t) ->
103 f (S.sh2 u xu t xt x (B.bind_abst n a)) (B.bind_abst (N.minus st n 1) a xu tt)
105 let f xu m = b_type_of err (f xu) st m t in
106 let f xu _ = f xu (BR.push m a (B.abst n xu)) in
108 | B.Bind (a, B.Void, t) ->
110 f (S.sh1 t xt x (B.bind_void a)) (B.bind_void a tt)
112 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 xv t xt x (B.appl a)) (B.appl a xv tt) in
117 assert_applicability err f st m tt vv xv
119 let f xv vv = b_type_of err (f xv vv) st m t in
121 | B.Cast (a, u, t) ->
123 let f _ = f (S.sh2 u xu t xt x (B.cast a)) xu in
124 assert_convertibility err f st m xu tt xt
126 let f xu _ = b_type_of err (f xu) st m t in
129 (* Interface functions ******************************************************)
131 and type_of err f st m x = b_type_of err f st m x