1 (* Copyright (C) 2002, HELM Team.
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.
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14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
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19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
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23 * http://cs.unibo.it/helm/.
30 module PET = ProofEngineTypes
31 module PER = ProofEngineReduction
32 module PEH = ProofEngineHelpers
33 module PESR = ProofEngineStructuralRules
34 module P = PrimitiveTactics
36 module R = CicReduction
37 module TC = CicTypeChecker
38 module LO = LibraryObjects
39 module DTI = DoubleTypeInference
41 let rec rewrite_tac ~direction ~(pattern: ProofEngineTypes.lazy_pattern) equality =
42 let _rewrite_tac ~direction ~pattern:(wanted,hyps_pat,concl_pat) equality status
44 assert (wanted = None); (* this should be checked syntactically *)
45 let proof,goal = status in
46 let curi, metasenv, pbo, pty = proof in
47 let (metano,context,gty) = CicUtil.lookup_meta goal metasenv in
52 (rewrite_tac ~direction
53 ~pattern:(None,[he],None) equality)
54 (rewrite_tac ~direction ~pattern:(None,tl,concl_pat)
55 (CicSubstitution.lift 1 equality))
57 | [_] as hyps_pat when concl_pat <> None ->
60 (rewrite_tac ~direction
61 ~pattern:(None,hyps_pat,None) equality)
62 (rewrite_tac ~direction ~pattern:(None,[],concl_pat)
63 (CicSubstitution.lift 1 equality))
66 let arg,dir2,tac,concl_pat,gty =
68 [] -> None,true,(fun ~term _ -> P.exact_tac term),concl_pat,gty
73 | Some (Cic.Name s,Cic.Decl ty)::_ when name = s ->
74 Cic.Rel n, CicSubstitution.lift n ty
75 | Some (Cic.Name s,Cic.Def _)::_ -> assert false (*CSC: not implemented yet! But does this make any sense?*)
76 | _::tl -> find_hyp (n+1) tl
78 let arg,gty = find_hyp 1 context in
79 let dummy = "dummy" in
84 [ProofEngineStructuralRules.rename name dummy;
86 ~mk_fresh_name_callback:(fun _ _ _ ~typ -> Cic.Name name) term;
87 ProofEngineStructuralRules.clearbody name;
88 ReductionTactics.change_tac
90 (None,[name,Cic.Implicit (Some `Hole)], None)
91 (ProofEngineTypes.const_lazy_term typ);
92 ProofEngineStructuralRules.clear [dummy]
95 | _::_ -> assert false
97 let if_right_to_left do_not_change a b =
99 | `RightToLeft -> if do_not_change then a else b
100 | `LeftToRight -> if do_not_change then b else a
103 CicTypeChecker.type_of_aux' metasenv context equality
104 CicUniv.empty_ugraph in
105 let (ty_eq,metasenv',arguments,fresh_meta) =
106 ProofEngineHelpers.saturate_term
107 (ProofEngineHelpers.new_meta_of_proof proof) metasenv context ty_eq 0 in
109 if List.length arguments = 0 then
112 C.Appl (equality :: arguments) in
113 (* t1x is t2 if we are rewriting in an hypothesis *)
114 let eq_ind, ty, t1, t2, t1x =
116 | C.Appl [C.MutInd (uri, 0, []); ty; t1; t2]
117 when LibraryObjects.is_eq_URI uri ->
119 if_right_to_left dir2
120 LibraryObjects.eq_ind_URI LibraryObjects.eq_ind_r_URI
122 let eq_ind = C.Const (ind_uri uri,[]) in
124 if_right_to_left true (eq_ind,ty,t2,t1,t2) (eq_ind,ty,t1,t2,t1)
126 if_right_to_left true (eq_ind,ty,t1,t2,t2) (eq_ind,ty,t2,t1,t1)
127 | _ -> raise (PET.Fail (lazy "Rewrite: argument is not a proof of an equality")) in
128 (* now we always do as if direction was `LeftToRight *)
130 FreshNamesGenerator.mk_fresh_name
131 ~subst:[] metasenv' context C.Anonymous ~typ:ty in
132 let lifted_t1 = CicSubstitution.lift 1 t1x in
133 let lifted_gty = CicSubstitution.lift 1 gty in
134 let lifted_conjecture =
135 metano,(Some (fresh_name,Cic.Decl ty))::context,lifted_gty in
137 let lifted_concl_pat =
140 | Some term -> Some (CicSubstitution.lift 1 term) in
141 Some (fun _ m u -> lifted_t1, m, u),[],lifted_concl_pat
143 let subst,metasenv',ugraph,_,selected_terms_with_context =
144 ProofEngineHelpers.select
145 ~metasenv:metasenv' ~ugraph ~conjecture:lifted_conjecture
146 ~pattern:lifted_pattern in
147 let metasenv' = CicMetaSubst.apply_subst_metasenv subst metasenv' in
149 (* Note: Rel 1 does not live in the context context_of_t *)
150 (* The replace_lifting_csc 0 function will take care of lifting it *)
151 (* to context_of_t *)
153 (fun (context_of_t,t) (l1,l2) -> t::l1, Cic.Rel 1::l2)
154 selected_terms_with_context ([],[]) in
155 let t1 = CicMetaSubst.apply_subst subst t1 in
156 let t2 = CicMetaSubst.apply_subst subst t2 in
157 let ty = CicMetaSubst.apply_subst subst ty in
158 let pbo = CicMetaSubst.apply_subst subst pbo in
159 let pty = CicMetaSubst.apply_subst subst pty in
160 let equality = CicMetaSubst.apply_subst subst equality in
162 ProofEngineReduction.replace_lifting_csc 0
163 ~equality:(==) ~what ~with_what:with_what ~where:lifted_gty in
164 let abstr_gty = CicMetaSubst.apply_subst subst abstr_gty in
165 let pred = C.Lambda (fresh_name, ty, abstr_gty) in
166 (* The argument is either a meta if we are rewriting in the conclusion
167 or the hypothesis if we are rewriting in an hypothesis *)
168 let metasenv',arg,newtyp =
171 let gty' = CicSubstitution.subst t2 abstr_gty in
173 CicMkImplicit.identity_relocation_list_for_metavariable context in
174 let metasenv' = (fresh_meta,context,gty')::metasenv' in
175 metasenv', C.Meta (fresh_meta,irl), Cic.Rel (-1) (* dummy term, never used *)
177 let gty' = CicSubstitution.subst t1 abstr_gty in
181 C.Appl [eq_ind ; ty ; t2 ; pred ; arg ; t1 ;equality]
186 (tac ~term:exact_proof newtyp) ((curi,metasenv',pbo,pty),goal)
189 goals@(ProofEngineHelpers.compare_metasenvs ~oldmetasenv:metasenv
190 ~newmetasenv:metasenv')
193 with (* FG: this should be PET.Fail _ *)
194 TC.TypeCheckerFailure _ ->
195 let msg = lazy "rewrite: nothing to rewrite" in
198 ProofEngineTypes.mk_tactic (_rewrite_tac ~direction ~pattern equality)
201 let rewrite_simpl_tac ~direction ~pattern equality =
202 let rewrite_simpl_tac ~direction ~pattern equality status =
203 ProofEngineTypes.apply_tactic
205 ~start:(rewrite_tac ~direction ~pattern equality)
207 (ReductionTactics.simpl_tac
208 ~pattern:(ProofEngineTypes.conclusion_pattern None)))
211 ProofEngineTypes.mk_tactic (rewrite_simpl_tac ~direction ~pattern equality)
214 let replace_tac ~(pattern: ProofEngineTypes.lazy_pattern) ~with_what =
215 let replace_tac ~(pattern: ProofEngineTypes.lazy_pattern) ~with_what status =
216 let _wanted, hyps_pat, concl_pat = pattern in
217 let (proof, goal) = status in
218 let uri,metasenv,pbo,pty = proof in
219 let (_,context,ty) as conjecture = CicUtil.lookup_meta goal metasenv in
220 assert (hyps_pat = []); (*CSC: not implemented yet *)
222 match LibraryObjects.eq_URI () with
224 | None -> raise (ProofEngineTypes.Fail (lazy "You need to register the default equality first. Please use the \"default\" command"))
226 let context_len = List.length context in
227 let subst,metasenv,u,_,selected_terms_with_context =
228 ProofEngineHelpers.select ~metasenv ~ugraph:CicUniv.empty_ugraph
229 ~conjecture ~pattern in
230 let metasenv = CicMetaSubst.apply_subst_metasenv subst metasenv in
231 let with_what, metasenv, u = with_what context metasenv u in
232 let with_what = CicMetaSubst.apply_subst subst with_what in
233 let pbo = CicMetaSubst.apply_subst subst pbo in
234 let pty = CicMetaSubst.apply_subst subst pty in
235 let status = (uri,metasenv,pbo,pty),goal in
236 let ty_of_with_what,u =
237 CicTypeChecker.type_of_aux'
238 metasenv context with_what CicUniv.empty_ugraph in
240 match selected_terms_with_context with
241 [] -> raise (ProofEngineTypes.Fail (lazy "Replace: no term selected"))
244 (fun (context_of_t,t) ->
247 let context_of_t_len = List.length context_of_t in
248 if context_of_t_len = context_len then t
250 (let t_in_context,subst,metasenv' =
251 CicMetaSubst.delift_rels [] metasenv
252 (context_of_t_len - context_len) t
255 assert (metasenv = metasenv');
258 CicMetaSubst.DeliftingARelWouldCaptureAFreeVariable ->
259 (*CSC: we could implement something stronger by completely changing
260 the semantics of the tactic *)
261 raise (ProofEngineTypes.Fail
262 (lazy "Replace: one of the selected terms is not closed")) in
263 let ty_of_t_in_context,u = (* TASSI: FIXME *)
264 CicTypeChecker.type_of_aux' metasenv context t_in_context
265 CicUniv.empty_ugraph in
266 let b,u = CicReduction.are_convertible ~metasenv context
267 ty_of_with_what ty_of_t_in_context u in
269 let concl_pat_for_t = ProofEngineHelpers.pattern_of ~term:ty [t] in
270 let pattern_for_t = None,[],Some concl_pat_for_t in
271 t_in_context,pattern_for_t
274 (ProofEngineTypes.Fail
275 (lazy "Replace: one of the selected terms and the term to be replaced with have not convertible types"))
277 let rec aux n whats status =
279 [] -> ProofEngineTypes.apply_tactic T.id_tac status
280 | (what,lazy_pattern)::tl ->
281 let what = CicSubstitution.lift n what in
282 let with_what = CicSubstitution.lift n with_what in
283 let ty_of_with_what = CicSubstitution.lift n ty_of_with_what in
284 ProofEngineTypes.apply_tactic
289 (C.MutInd (eq_URI, 0, [])) ;
296 rewrite_tac ~direction:`LeftToRight ~pattern:lazy_pattern (C.Rel 1))
300 ProofEngineTypes.mk_tactic
301 (function ((proof,goal) as status) ->
302 let _,metasenv,_,_ = proof in
303 let _,context,_ = CicUtil.lookup_meta goal metasenv in
306 match List.hd context with
307 Some (Cic.Name name,_) -> [name]
309 with (Failure "hd") -> assert false
311 ProofEngineTypes.apply_tactic
312 (ProofEngineStructuralRules.clear ~hyps) status))
313 ~continuation:(aux_tac (n + 1) tl));
316 and aux_tac n tl = ProofEngineTypes.mk_tactic (aux n tl) in
319 ProofEngineTypes.mk_tactic (replace_tac ~pattern ~with_what)
323 (* All these tacs do is applying the right constructor/theorem *)
325 let reflexivity_tac =
326 IntroductionTactics.constructor_tac ~n:1
330 let symmetry_tac (proof, goal) =
331 let (_,metasenv,_,_) = proof in
332 let metano,context,ty = CicUtil.lookup_meta goal metasenv in
333 match (R.whd context ty) with
334 (C.Appl [(C.MutInd (uri, 0, [])); _; _; _])
335 when LibraryObjects.is_eq_URI uri ->
336 ProofEngineTypes.apply_tactic
337 (PrimitiveTactics.apply_tac
338 ~term: (C.Const (LibraryObjects.sym_eq_URI uri, [])))
341 | _ -> raise (ProofEngineTypes.Fail (lazy "Symmetry failed"))
343 ProofEngineTypes.mk_tactic symmetry_tac
346 let transitivity_tac ~term =
347 let transitivity_tac ~term status =
348 let (proof, goal) = status in
349 let (_,metasenv,_,_) = proof in
350 let metano,context,ty = CicUtil.lookup_meta goal metasenv in
351 match (R.whd context ty) with
352 (C.Appl [(C.MutInd (uri, 0, [])); _; _; _])
353 when LibraryObjects.is_eq_URI uri ->
354 ProofEngineTypes.apply_tactic
356 ~start:(PrimitiveTactics.apply_tac
357 ~term: (C.Const (LibraryObjects.trans_eq_URI uri, [])))
359 [PrimitiveTactics.exact_tac ~term ; T.id_tac ; T.id_tac])
362 | _ -> raise (ProofEngineTypes.Fail (lazy "Transitivity failed"))
364 ProofEngineTypes.mk_tactic (transitivity_tac ~term)
367 (* FG: subst tactic *********************************************************)
369 (* FG: This should be replaced by T.try_tactic *)
370 let try_tactic ~tactic =
371 let try_tactic status =
372 try PET.apply_tactic tactic status with
373 | PET.Fail _ -> PET.apply_tactic T.id_tac status
375 PET.mk_tactic try_tactic
377 let msg0 = lazy "Subst: not found in context"
378 let msg1 = lazy "Subst: not a simple equality"
379 let msg2 = lazy "Subst: recursive equation"
382 let hole = C.Implicit (Some `Hole) in
383 let subst_tac status =
384 let (proof, goal) = status in
385 let (_, metasenv, _, _) = proof in
386 let _, context, _ = CicUtil.lookup_meta goal metasenv in
387 let what = match PEH.get_rel context hyp with
389 | None -> raise (PET.Fail msg0)
391 let ty, _ = TC.type_of_aux' metasenv context what CicUniv.empty_ugraph in
392 let direction, i, t = match ty with
393 | (C.Appl [(C.MutInd (uri, 0, [])); _; C.Rel i; t])
394 when LO.is_eq_URI uri -> `LeftToRight, i, t
395 | (C.Appl [(C.MutInd (uri, 0, [])); _; t; C.Rel i])
396 when LO.is_eq_URI uri -> `RightToLeft, i, t
397 | _ -> raise (PET.Fail msg1)
399 let rewrite pattern =
400 try_tactic ~tactic:(rewrite_tac ~direction ~pattern what)
402 let var = match PEH.get_name context i with
404 | None -> raise (PET.Fail msg0)
406 if DTI.does_not_occur i t then () else raise (PET.Fail msg2);
407 let map self = function
408 | Some (C.Name s, _) when s <> self ->
409 Some (rewrite (None, [(s, hole)], None))
412 let rew_hips = PEH.list_rev_map_filter (map hyp) context in
413 let rew_concl = rewrite (None, [], Some hole) in
414 let clear = PESR.clear ~hyps:[hyp; var] in
415 let tactics = List.rev_append (rew_concl :: rew_hips) [clear] in
416 PET.apply_tactic (T.seq ~tactics) status
418 PET.mk_tactic subst_tac
421 let subst hyp = try_tactic ~tactic:(subst_tac hyp) in
423 | Some (C.Name s, _) -> Some (subst s)
426 let subst_tac status =
427 let (proof, goal) = status in
428 let (_, metasenv, _, _) = proof in
429 let _, context, _ = CicUtil.lookup_meta goal metasenv in
430 let tactics = PEH.list_rev_map_filter map context in
431 PET.apply_tactic (T.seq ~tactics) status
433 PET.mk_tactic subst_tac