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_______________________________________________________________ *)
20 module BE = BrgEnvironment
21 module BS = BrgSubstitution
22 module BR = BrgReduction
24 type message = (BR.kam, B.term) Log.message
26 (* Internal functions *******************************************************)
30 let message1 st1 m t1 =
31 L.et_items1 "In the environment" m st1 t1
34 let s = s ^ " the term" in
35 L.log BR.specs level (message1 s m t)
37 let error1 err s m t =
40 let message3 m t1 t2 ?mu t3 =
41 let sm, st1, st2 = "In the environment", "the term", "is of type" in
44 let smu, st3 = "but in the environment", "it must be of type" in
45 L.et_items3 sm m st1 t1 st2 t2 ~sc3:smu ~c3:mu st3 t3
47 let st3 = "but it must be of type" in
48 L.et_items3 sm m st1 t1 st2 t2 st3 t3
50 let error3 err m t1 t2 ?mu t3 =
51 err (message3 m t1 t2 ?mu t3)
53 let assert_convertibility err f st m u w v =
54 if BR.are_convertible st m u m w then f () else
57 let assert_applicability err f st m u w v =
58 match BR.xwhd st m u with
60 error1 err "not a function type" m u
61 | mu, B.Bind (_, B.Abst (_, u), _) ->
62 if BR.are_convertible st mu u m w then f () else
63 error3 err m v w ~mu u
64 | _ -> assert false (**)
66 let rec b_type_of err f st m x =
67 log1 "Now checking" m x;
70 let h = H.apply h in f x (B.Sort (a, h))
72 begin match BR.get m i with
74 f x (BS.lift (succ i) (0) w)
75 | B.Abbr (B.Cast (_, w, _)) ->
76 f x (BS.lift (succ i) (0) w)
77 | B.Abbr _ -> assert false
79 error1 err "reference to excluded variable" m x
82 begin match BE.get_entity uri with
83 | _, _, E.Abst (_, w) -> f x w
84 | _, _, E.Abbr (B.Cast (_, w, _)) -> f x w
85 | _, _, E.Abbr _ -> assert false
87 error1 err "reference to unknown entry" m x
89 | B.Bind (a, B.Abbr v, t) ->
91 f (W.sh2 v xv t xt x (B.bind_abbr a)) (B.bind_abbr a xv tt)
93 let f xv m = b_type_of err (f xv) st m t in
94 let f xv = f xv (BR.push m a (B.abbr xv)) in
95 let f xv vv = match xv with
97 | _ -> f (B.Cast ([], vv, xv))
100 | B.Bind (a, B.Abst (n, u), t) ->
102 f (W.sh2 u xu t xt x (B.bind_abst n a)) (B.bind_abst (N.pred n) a xu tt)
104 let f xu m = b_type_of err (f xu) st m t in
105 let f xu _ = f xu (BR.push m a (B.abst n xu)) in
107 | B.Bind (a, B.Void, t) ->
109 f (W.sh1 t xt x (B.bind_void a)) (B.bind_void a tt)
111 b_type_of err f st (BR.push m a B.Void) t
113 | B.Appl (a, v, t) ->
115 let f _ = f (W.sh2 v xv t xt x (B.appl a)) (B.appl a xv tt) in
116 assert_applicability err f st m tt vv xv
118 let f xv vv = b_type_of err (f xv vv) st m t in
120 | B.Cast (a, u, t) ->
122 let f _ = f (W.sh2 u xu t xt x (B.cast a)) xu in
123 assert_convertibility err f st m xu tt xt
125 let f xu _ = b_type_of err (f xu) st m t in
128 (* Interface functions ******************************************************)
130 and type_of err f st m x =
131 let f t u = L.unbox level; f t u in
132 L.box level; b_type_of err f st m x