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_______________________________________________________________ *)
19 module E = BrgEnvironment
20 module S = BrgSubstitution
21 module R = BrgReduction
23 exception TypeError of B.message
25 (* Internal functions *******************************************************)
30 let s = s ^ " the term" in
31 L.log O.specs level (R.message1 s m t)
34 raise (TypeError (R.message1 s m t))
36 let message3 m t1 t2 ?mu t3 =
37 let st1, st2 = "the term", "is of type" in
40 let smu, st3 = "but in the context", "it must be of type" in
41 R.message3 st1 st2 ~sm3:smu st3 m t1 t2 ~m3:mu t3
43 let st3 = "but it must be of type" in
44 R.message3 st1 st2 st3 m t1 t2 t3
46 let error3 m t1 t2 ?mu t3 =
47 raise (TypeError (message3 m t1 t2 ?mu t3))
49 let assert_convertibility f ~si m u w v =
50 let err () = error3 m v w u in
51 R.are_convertible err f ~si m u m w
53 let assert_applicability f ~si m u w v =
55 | B.Bind (B.Abst (_, u), _) ->
56 let err () = error3 m v w ~mu u in
57 R.are_convertible err f ~si mu u m w
58 | _ -> error1 "not a function type" m u
62 let rec b_type_of f ~si g m x =
63 log1 "Now checking" m x;
66 let f h = f x (B.Sort (a, h)) in H.apply f g h
70 S.lift (f x) (succ i) (0) w
71 | B.Abbr (_, B.Cast (_, w, _)) ->
72 S.lift (f x) (succ i) (0) w
73 | B.Abbr _ -> assert false
75 error1 "reference to excluded variable" m x
80 | _, _, B.Abst (_, w) -> f x w
81 | _, _, B.Abbr (_, B.Cast (_, w, _)) -> f x w
82 | _, _, B.Abbr _ -> assert false
84 error1 "reference to excluded object" m x
87 | B.Bind (B.Abbr (a, v), t) ->
89 f (A.sh2 v xv t xt x (B.bind_abbr a)) (B.bind_abbr a xv tt)
91 let f xv m = b_type_of (f xv) ~si g m t in
92 let f xv = R.push (f xv) m (B.abbr a xv) in
93 let f xv vv = match xv with
95 | _ -> f (B.Cast ([], vv, xv))
98 | B.Bind (B.Abst (a, u), t) ->
100 f (A.sh2 u xu t xt x (B.bind_abst a)) (B.bind_abst a xu tt)
102 let f xu m = b_type_of (f xu) ~si g m t in
103 let f xu _ = R.push (f xu) m (B.abst a xu) in
105 | B.Bind (B.Void a as b, t) ->
107 f (A.sh1 t xt x (B.bind b)) (B.bind b tt)
109 let f m = b_type_of f ~si g m t in
111 | B.Appl (a, v, t) ->
113 let f () = f (A.sh2 v xv t xt x (B.appl a)) (B.appl a xv tt) in
114 assert_applicability f ~si m tt vv xv
116 let f xv vv = b_type_of (f xv vv) ~si g m t in
118 | B.Cast (a, u, t) ->
120 let f () = f (A.sh2 u xu t xt x (B.cast a)) xu in
121 assert_convertibility f ~si m xu tt xt
123 let f xu _ = b_type_of (f xu) ~si g m t in
126 (* Interface functions ******************************************************)
128 and type_of f ?(si=false) g m x =
129 let f t u = L.unbox level; f t u in
130 L.box level; b_type_of f ~si g m x