helm/gTopLevel/proofEngineStructuralRules.ml

   1 (* Copyright (C) 2002, HELM Team.
   2  *
   3  * This file is part of HELM, an Hypertextual, Electronic
   4  * Library of Mathematics, developed at the Computer Science
   5  * Department, University of Bologna, Italy.
   6  *
   7  * HELM is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  *
  12  * HELM is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with HELM; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  20  * MA  02111-1307, USA.
  21  *
  22  * For details, see the HELM World-Wide-Web page,
  23  * http://cs.unibo.it/helm/.
  24  *)
  25
  26 open ProofEngineTypes
  27
  28 let clearbody ~hyp ~status:(proof, goal) =
  29  let module C = Cic in
  30   match hyp with
  31      None -> assert false
  32    | Some (_, C.Decl _) -> raise (Fail "No Body To Clear")
  33    | Some (n_to_clear_body, C.Def term) as hyp_to_clear_body ->
  34       let curi,metasenv,pbo,pty = proof in
  35        let metano,_,_ = List.find (function (m,_,_) -> m=goal) metasenv in
  36         let string_of_name =
  37          function
  38             C.Name n -> n
  39           | C.Anonimous -> "_"
  40         in
  41         let metasenv' =
  42          List.map
  43           (function
  44               (m,canonical_context,ty) when m = metano ->
  45                 let canonical_context' =
  46                  List.fold_right
  47                   (fun entry context ->
  48                     match entry with
  49                        t when t == hyp_to_clear_body ->
  50                         let cleared_entry =
  51                          let ty =
  52                           CicTypeChecker.type_of_aux' metasenv context term
  53                          in
  54                           Some (n_to_clear_body, Cic.Decl ty)
  55                         in
  56                          cleared_entry::context
  57                      | None -> None::context
  58                      | Some (n,C.Decl t)
  59                      | Some (n,C.Def t) ->
  60                         let _ =
  61                          try
  62                           CicTypeChecker.type_of_aux' metasenv context t
  63                          with
  64                           _ ->
  65                             raise
  66                              (Fail
  67                                ("The correctness of hypothesis " ^
  68                                 string_of_name n ^
  69                                 " relies on the body of " ^
  70                                 string_of_name n_to_clear_body)
  71                              )
  72                         in
  73                          entry::context
  74                   ) canonical_context []
  75                 in
  76                  let _ =
  77                   try
  78                    CicTypeChecker.type_of_aux' metasenv canonical_context' ty
  79                   with
  80                    _ ->
  81                     raise
  82                      (Fail
  83                       ("The correctness of the goal relies on the body of " ^
  84                        string_of_name n_to_clear_body))
  85                  in
  86                   m,canonical_context',ty
  87             | t -> t
  88           ) metasenv
  89         in
  90          (curi,metasenv',pbo,pty), [goal]
  91
  92 let clear ~hyp:hyp_to_clear ~status:(proof, goal) =
  93  let module C = Cic in
  94   match hyp_to_clear with
  95      None -> assert false
  96    | Some (n_to_clear, _) ->
  97       let curi,metasenv,pbo,pty = proof in
  98        let metano,context,ty =
  99         List.find (function (m,_,_) -> m=goal) metasenv
 100        in
 101         let string_of_name =
 102          function
 103             C.Name n -> n
 104           | C.Anonimous -> "_"
 105         in
 106         let metasenv' =
 107          List.map
 108           (function
 109               (m,canonical_context,ty) when m = metano ->
 110                 let canonical_context' =
 111                  List.fold_right
 112                   (fun entry context ->
 113                     match entry with
 114                        t when t == hyp_to_clear -> None::context
 115                      | None -> None::context
 116                      | Some (n,C.Decl t)
 117                      | Some (n,C.Def t) ->
 118                         let _ =
 119                          try
 120                           CicTypeChecker.type_of_aux' metasenv context t
 121                          with
 122                           _ ->
 123                             raise
 124                              (Fail
 125                                ("Hypothesis " ^
 126                                 string_of_name n ^
 127                                 " uses hypothesis " ^
 128                                 string_of_name n_to_clear)
 129                              )
 130                         in
 131                          entry::context
 132                   ) canonical_context []
 133                 in
 134                  let _ =
 135                   try
 136                    CicTypeChecker.type_of_aux' metasenv canonical_context' ty
 137                   with
 138                    _ ->
 139                     raise
 140                      (Fail
 141                       ("Hypothesis " ^ string_of_name n_to_clear ^
 142                        " occurs in the goal"))
 143                  in
 144                   m,canonical_context',ty
 145             | t -> t
 146           ) metasenv
 147         in
 148          (curi,metasenv',pbo,pty), [goal]
 149