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
27 (* Internal functions *******************************************************)
31 let message1 st1 m t1 =
32 L.et_items1 "In the environment" m st1 t1
35 let s = s ^ " the term" in
36 L.log st BR.specs (pred level) (message1 s m t)
38 let error1 err s m t =
41 let message3 m t1 t2 ?mu t3 =
42 let sm, st1, st2 = "In the environment", "the term", "is of type" in
45 let smu, st3 = "but in the environment", "it must be of type" in
46 L.et_items3 sm m st1 t1 st2 t2 ~sc3:smu ~c3:mu st3 t3
48 let st3 = "but it must be of type" in
49 L.et_items3 sm m st1 t1 st2 t2 st3 t3
51 let error3 err m t1 t2 ?mu t3 =
52 err (message3 m t1 t2 ?mu t3)
56 let assert_convertibility err f st m u w v =
57 if BR.are_convertible st m zero u m zero w then f () else
60 let assert_applicability err f st m a u w v =
61 let mode = if a.E.a_rest then zero else None in
62 match BR.xwhd st m mode u with
64 error1 err "not a function type" m u
65 | mu, B.Bind (_, B.Abst (true, n, u), _) ->
66 if !G.cc && not (N.assert_not_zero st n) then error1 err "not a function type" m u else
67 if BR.are_convertible st mu zero u m zero w then f () else
68 error3 err m v w ~mu u
69 | _ -> assert false (**)
71 let rec b_type_of err f st m z =
73 if !G.ct >= level then log1 st "Now checking" m z
77 let k = H.apply k in f z (B.Sort k)
79 begin match BR.get m i with
81 f z (BS.lift (succ i) (0) w)
82 | B.Abbr (B.Cast (w, _)) ->
83 f z (BS.lift (succ i) (0) w)
84 | B.Abbr _ -> assert false
86 error1 err "reference to excluded variable" m z
89 begin match BE.get_entity u with
90 | _, _, _, E.Abst (_, w) -> f z w
91 | _, _, _, E.Abbr (_, B.Cast (w, _)) -> f z w
92 | _, _, _, E.Abbr _ -> assert false
94 error1 err "reference to unknown entry" m z
96 | B.Bind (y, B.Abbr v, t) ->
98 f (S.sh2 v rv t rt z (B.bind_abbr y)) (B.bind_abbr y rv tt)
100 let f rv m = b_type_of err (f rv) st m t in
101 let f rv = f rv (BR.push m y (B.abbr rv)) in
102 let f rv vv = match rv with
104 | _ -> f (B.Cast (vv, rv))
107 | B.Bind (y, B.Abst (r, n, u), t) ->
109 f (S.sh2 u ru t rt z (B.bind_abst r n y)) (B.bind_abst r (N.minus st n 1) y ru tt)
111 let f ru m = b_type_of err (f ru) st m t in
112 let f ru _ = f ru (BR.push m y (B.abst r n ru)) in
114 | B.Bind (y, B.Void, t) ->
116 f (S.sh1 t rt z (B.bind_void y)) (B.bind_void y tt)
118 b_type_of err f st (BR.push m y B.Void) t
119 | B.Appl (a, v, t) ->
121 let f _ = f (S.sh2 v rv t rt z (B.appl a)) (B.appl a rv tt) in
122 assert_applicability err f st m a tt vv rv
124 let f rv vv = b_type_of err (f rv vv) st m t in
128 let f _ = f (S.sh2 u ru t rt z (B.cast)) ru in
129 assert_convertibility err f st m ru tt rt
131 let f ru _ = b_type_of err (f ru) st m t in
134 (* Interface functions ******************************************************)
136 and type_of err f st m t = b_type_of err f st m t