(************************************************************************) (* v * The Coq Proof Assistant / The Coq Development Team *) (* catchable_exception e | LtacLocated(_,e) -> catchable_exception e | Util.UserError _ | TypeError _ | RefinerError _ | Indrec.RecursionSchemeError _ | Nametab.GlobalizationError _ | PretypeError (_,VarNotFound _) (* reduction errors *) | Tacred.ReductionTacticError _ (* unification errors *) | PretypeError(_,(CannotUnify _|CannotUnifyLocal _|CannotGeneralize _ |NoOccurrenceFound _|CannotUnifyBindingType _|NotClean _ |CannotFindWellTypedAbstraction _|OccurCheck _ |UnsolvableImplicit _)) -> true | Typeclasses_errors.TypeClassError (_, Typeclasses_errors.UnsatisfiableConstraints _) -> true | _ -> false let error_no_such_hypothesis id = error ("No such hypothesis: " ^ string_of_id id ^ ".") (* Tells if the refiner should check that the submitted rules do not produce invalid subgoals *) let check = ref false let with_check = Flags.with_option check (* [apply_to_hyp sign id f] splits [sign] into [tail::[id,_,_]::head] and returns [tail::(f head (id,_,_) (rev tail))] *) let apply_to_hyp sign id f = try apply_to_hyp sign id f with Hyp_not_found -> if !check then error "No such assumption." else sign let apply_to_hyp_and_dependent_on sign id f g = try apply_to_hyp_and_dependent_on sign id f g with Hyp_not_found -> if !check then error "No such assumption." else sign let check_typability env sigma c = if !check then let _ = type_of env sigma c in () (************************************************************************) (************************************************************************) (* Implementation of the structural rules (moving and deleting hypotheses around) *) (* The Clear tactic: it scans the context for hypotheses to be removed (instead of iterating on the list of identifier to be removed, which forces the user to give them in order). *) let clear_hyps sigma ids sign cl = let evdref = ref (Evd.create_goal_evar_defs sigma) in let (hyps,concl) = Evarutil.clear_hyps_in_evi evdref sign cl ids in (hyps,concl, !evdref) (* The ClearBody tactic *) let recheck_typability (what,id) env sigma t = try check_typability env sigma t with _ -> let s = match what with | None -> "the conclusion" | Some id -> "hypothesis "^(string_of_id id) in error ("The correctness of "^s^" relies on the body of "^(string_of_id id)) let remove_hyp_body env sigma id = let sign = apply_to_hyp_and_dependent_on (named_context_val env) id (fun (_,c,t) _ -> match c with | None -> error ((string_of_id id)^" is not a local definition.") | Some c ->(id,None,t)) (fun (id',c,t as d) sign -> (if !check then begin let env = reset_with_named_context sign env in match c with | None -> recheck_typability (Some id',id) env sigma t | Some b -> let b' = mkCast (b,DEFAULTcast, t) in recheck_typability (Some id',id) env sigma b' end;d)) in reset_with_named_context sign env (* Reordering of the context *) (* faire le minimum d'echanges pour que l'ordre donne soit un *) (* sous-ordre du resultat. Par exemple, 2 hyps non mentionnee ne sont *) (* pas echangees. Choix: les hyps mentionnees ne peuvent qu'etre *) (* reculees par rapport aux autres (faire le contraire!) *) let mt_q = (Idmap.empty,[]) let push_val y = function (_,[] as q) -> q | (m, (x,l)::q) -> (m, (x,Idset.add y l)::q) let push_item x v (m,l) = (Idmap.add x v m, (x,Idset.empty)::l) let mem_q x (m,_) = Idmap.mem x m let rec find_q x (m,q) = let v = Idmap.find x m in let m' = Idmap.remove x m in let rec find accs acc = function [] -> raise Not_found | [(x',l)] -> if x=x' then ((v,Idset.union accs l),(m',List.rev acc)) else raise Not_found | (x',l as i)::((x'',l'')::q as itl) -> if x=x' then ((v,Idset.union accs l), (m',List.rev acc@(x'',Idset.add x (Idset.union l l''))::q)) else find (Idset.union l accs) (i::acc) itl in find Idset.empty [] q let occur_vars_in_decl env hyps d = if Idset.is_empty hyps then false else let ohyps = global_vars_set_of_decl env d in Idset.exists (fun h -> Idset.mem h ohyps) hyps let reorder_context env sign ord = let ords = List.fold_right Idset.add ord Idset.empty in if List.length ord <> Idset.cardinal ords then error "Order list has duplicates"; let rec step ord expected ctxt_head moved_hyps ctxt_tail = match ord with | [] -> List.rev ctxt_tail @ ctxt_head | top::ord' when mem_q top moved_hyps -> let ((d,h),mh) = find_q top moved_hyps in if occur_vars_in_decl env h d then errorlabstrm "reorder_context" (str "Cannot move declaration " ++ pr_id top ++ spc() ++ str "before " ++ prlist_with_sep pr_spc pr_id (Idset.elements (Idset.inter h (global_vars_set_of_decl env d)))); step ord' expected ctxt_head mh (d::ctxt_tail) | _ -> (match ctxt_head with | [] -> error_no_such_hypothesis (List.hd ord) | (x,_,_ as d) :: ctxt -> if Idset.mem x expected then step ord (Idset.remove x expected) ctxt (push_item x d moved_hyps) ctxt_tail else step ord expected ctxt (push_val x moved_hyps) (d::ctxt_tail)) in step ord ords sign mt_q [] let reorder_val_context env sign ord = val_of_named_context (reorder_context env (named_context_of_val sign) ord) let check_decl_position env sign (x,_,_ as d) = let needed = global_vars_set_of_decl env d in let deps = dependency_closure env (named_context_of_val sign) needed in if List.mem x deps then error ("Cannot create self-referring hypothesis "^string_of_id x); x::deps (* Auxiliary functions for primitive MOVE tactic * * [move_hyp with_dep toleft (left,(hfrom,typfrom),right) hto] moves * hyp [hfrom] at location [hto] which belongs to the hyps on the * left side [left] of the full signature if [toleft=true] or to the hyps * on the right side [right] if [toleft=false]. * If [with_dep] then dependent hypotheses are moved accordingly. *) let rec get_hyp_after h = function | [] -> error_no_such_hypothesis h | (hyp,_,_) :: right -> if hyp = h then match right with (id,_,_)::_ -> MoveBefore id | [] -> MoveToEnd false else get_hyp_after h right let split_sign hfrom hto l = let rec splitrec left toleft = function | [] -> error_no_such_hypothesis hfrom | (hyp,c,typ) as d :: right -> if hyp = hfrom then (left,right,d, toleft or hto = MoveToEnd true) else splitrec (d::left) (toleft or hto = MoveAfter hyp or hto = MoveBefore hyp) right in splitrec [] false l let hyp_of_move_location = function | MoveAfter id -> id | MoveBefore id -> id | _ -> assert false let move_hyp with_dep toleft (left,(idfrom,_,_ as declfrom),right) hto = let env = Global.env() in let test_dep (hyp,c,typ as d) (hyp2,c,typ2 as d2) = if toleft then occur_var_in_decl env hyp2 d else occur_var_in_decl env hyp d2 in let rec moverec first middle = function | [] -> if match hto with MoveToEnd _ -> false | _ -> true then error_no_such_hypothesis (hyp_of_move_location hto); List.rev first @ List.rev middle | (hyp,_,_) :: _ as right when hto = MoveBefore hyp -> List.rev first @ List.rev middle @ right | (hyp,_,_) as d :: right -> let (first',middle') = if List.exists (test_dep d) middle then if with_dep & hto <> MoveAfter hyp then (first, d::middle) else errorlabstrm "move_hyp" (str "Cannot move " ++ pr_id idfrom ++ pr_move_location pr_id hto ++ str (if toleft then ": it occurs in " else ": it depends on ") ++ pr_id hyp ++ str ".") else (d::first, middle) in if hto = MoveAfter hyp then List.rev first' @ List.rev middle' @ right else moverec first' middle' right in if toleft then let right = List.fold_right push_named_context_val right empty_named_context_val in List.fold_left (fun sign d -> push_named_context_val d sign) right (moverec [] [declfrom] left) else let right = List.fold_right push_named_context_val (moverec [] [declfrom] right) empty_named_context_val in List.fold_left (fun sign d -> push_named_context_val d sign) right left let rename_hyp id1 id2 sign = apply_to_hyp_and_dependent_on sign id1 (fun (_,b,t) _ -> (id2,b,t)) (fun d _ -> map_named_declaration (replace_vars [id1,mkVar id2]) d) (************************************************************************) (************************************************************************) (* Implementation of the logical rules *) (* Will only be used on terms given to the Refine rule which have meta variables only in Application and Case *) let error_unsupported_deep_meta c = errorlabstrm "" (strbrk "Application of lemmas whose beta-iota normal " ++ strbrk "form contains metavariables deep inside the term is not " ++ strbrk "supported; try \"refine\" instead.") let collect_meta_variables c = let rec collrec deep acc c = match kind_of_term c with | Meta mv -> if deep then error_unsupported_deep_meta () else mv::acc | Cast(c,_,_) -> collrec deep acc c | (App _| Case _) -> fold_constr (collrec deep) acc c | _ -> fold_constr (collrec true) acc c in List.rev (collrec false [] c) let check_meta_variables c = if not (list_distinct (collect_meta_variables c)) then raise (RefinerError (NonLinearProof c)) let check_conv_leq_goal env sigma arg ty conclty = if !check & not (is_conv_leq env sigma ty conclty) then raise (RefinerError (BadType (arg,ty,conclty))) let goal_type_of env sigma c = (if !check then type_of else Retyping.get_type_of ~refresh:true) env sigma c let rec mk_refgoals sigma goal goalacc conclty trm = let env = evar_env goal in let hyps = goal.evar_hyps in let mk_goal hyps concl = mk_goal hyps concl goal.evar_extra in (* if not (occur_meta trm) then let t'ty = (unsafe_machine env sigma trm).uj_type in let _ = conv_leq_goal env sigma trm t'ty conclty in (goalacc,t'ty) else *) match kind_of_term trm with | Meta _ -> let conclty = nf_betaiota sigma conclty in if !check && occur_meta conclty then raise (RefinerError (MetaInType conclty)); (mk_goal hyps conclty)::goalacc, conclty | Cast (t,_, ty) -> check_typability env sigma ty; check_conv_leq_goal env sigma trm ty conclty; mk_refgoals sigma goal goalacc ty t | App (f,l) -> let (acc',hdty) = match kind_of_term f with | Ind _ | Const _ when (isInd f or has_polymorphic_type (destConst f)) -> (* Sort-polymorphism of definition and inductive types *) goalacc, type_of_global_reference_knowing_conclusion env sigma f conclty | _ -> mk_hdgoals sigma goal goalacc f in let (acc'',conclty') = mk_arggoals sigma goal acc' hdty (Array.to_list l) in check_conv_leq_goal env sigma trm conclty' conclty; (acc'',conclty') | Case (_,p,c,lf) -> let (acc',lbrty,conclty') = mk_casegoals sigma goal goalacc p c in check_conv_leq_goal env sigma trm conclty' conclty; let acc'' = array_fold_left2 (fun lacc ty fi -> fst (mk_refgoals sigma goal lacc ty fi)) acc' lbrty lf in (acc'',conclty') | _ -> if occur_meta trm then anomaly "refiner called with a meta in non app/case subterm"; let t'ty = goal_type_of env sigma trm in check_conv_leq_goal env sigma trm t'ty conclty; (goalacc,t'ty) (* Same as mkREFGOALS but without knowing te type of the term. Therefore, * Metas should be casted. *) and mk_hdgoals sigma goal goalacc trm = let env = evar_env goal in let hyps = goal.evar_hyps in let mk_goal hyps concl = mk_goal hyps concl goal.evar_extra in match kind_of_term trm with | Cast (c,_, ty) when isMeta c -> check_typability env sigma ty; (mk_goal hyps (nf_betaiota sigma ty))::goalacc,ty | Cast (t,_, ty) -> check_typability env sigma ty; mk_refgoals sigma goal goalacc ty t | App (f,l) -> let (acc',hdty) = if isInd f or isConst f & not (array_exists occur_meta l) (* we could be finer *) then (goalacc,type_of_global_reference_knowing_parameters env sigma f l) else mk_hdgoals sigma goal goalacc f in mk_arggoals sigma goal acc' hdty (Array.to_list l) | Case (_,p,c,lf) -> let (acc',lbrty,conclty') = mk_casegoals sigma goal goalacc p c in let acc'' = array_fold_left2 (fun lacc ty fi -> fst (mk_refgoals sigma goal lacc ty fi)) acc' lbrty lf in (acc'',conclty') | _ -> if !check && occur_meta trm then anomaly "refine called with a dependent meta"; goalacc, goal_type_of env sigma trm and mk_arggoals sigma goal goalacc funty = function | [] -> goalacc,funty | harg::tlargs as allargs -> let t = whd_betadeltaiota (evar_env goal) sigma funty in match kind_of_term t with | Prod (_,c1,b) -> let (acc',hargty) = mk_refgoals sigma goal goalacc c1 harg in mk_arggoals sigma goal acc' (subst1 harg b) tlargs | LetIn (_,c1,_,b) -> mk_arggoals sigma goal goalacc (subst1 c1 b) allargs | _ -> raise (RefinerError (CannotApply (t,harg))) and mk_casegoals sigma goal goalacc p c = let env = evar_env goal in let (acc',ct) = mk_hdgoals sigma goal goalacc c in let (acc'',pt) = mk_hdgoals sigma goal acc' p in let indspec = try find_mrectype env sigma ct with Not_found -> anomaly "mk_casegoals" in let (lbrty,conclty) = type_case_branches_with_names env indspec p c in (acc'',lbrty,conclty) let convert_hyp sign sigma (id,b,bt as d) = let env = Global.env() in let reorder = ref [] in let sign' = apply_to_hyp sign id (fun _ (_,c,ct) _ -> let env = Global.env_of_context sign in if !check && not (is_conv env sigma bt ct) then error ("Incorrect change of the type of "^(string_of_id id)^"."); if !check && not (Option.Misc.compare (is_conv env sigma) b c) then error ("Incorrect change of the body of "^(string_of_id id)^"."); if !check then reorder := check_decl_position env sign d; d) in reorder_val_context env sign' !reorder (* Normalizing evars in a goal. Called by tactic Local_constraints (i.e. when the sigma of the proof tree changes). Detect if the goal is unchanged *) let norm_goal sigma gl = let red_fun = Evarutil.nf_evar sigma in let ncl = red_fun gl.evar_concl in let ngl = { gl with evar_concl = ncl; evar_hyps = map_named_val red_fun gl.evar_hyps } in if Evd.eq_evar_info ngl gl then None else Some ngl (************************************************************************) (************************************************************************) (* Primitive tactics are handled here *) let prim_refiner r sigma goal = let env = evar_env goal in let sign = goal.evar_hyps in let cl = goal.evar_concl in let mk_goal hyps concl = mk_goal hyps concl goal.evar_extra in match r with (* Logical rules *) | Intro id -> if !check && mem_named_context id (named_context_of_val sign) then error ("Variable " ^ string_of_id id ^ " is already declared."); (match kind_of_term (strip_outer_cast cl) with | Prod (_,c1,b) -> let sg = mk_goal (push_named_context_val (id,None,c1) sign) (subst1 (mkVar id) b) in ([sg], sigma) | LetIn (_,c1,t1,b) -> let sg = mk_goal (push_named_context_val (id,Some c1,t1) sign) (subst1 (mkVar id) b) in ([sg], sigma) | _ -> raise (RefinerError IntroNeedsProduct)) | Cut (b,replace,id,t) -> let sg1 = mk_goal sign (nf_betaiota sigma t) in let sign,cl,sigma = if replace then let nexthyp = get_hyp_after id (named_context_of_val sign) in let sign,cl,sigma = clear_hyps sigma [id] sign cl in move_hyp true false ([],(id,None,t),named_context_of_val sign) nexthyp, cl,sigma else (if !check && mem_named_context id (named_context_of_val sign) then error ("Variable " ^ string_of_id id ^ " is already declared."); push_named_context_val (id,None,t) sign,cl,sigma) in let sg2 = mk_goal sign cl in if b then ([sg1;sg2],sigma) else ([sg2;sg1],sigma) | FixRule (f,n,rest,j) -> let rec check_ind env k cl = match kind_of_term (strip_outer_cast cl) with | Prod (na,c1,b) -> if k = 1 then try fst (find_inductive env sigma c1) with Not_found -> error "Cannot do a fixpoint on a non inductive type." else check_ind (push_rel (na,None,c1) env) (k-1) b | _ -> error "Not enough products." in let (sp,_) = check_ind env n cl in let firsts,lasts = list_chop j rest in let all = firsts@(f,n,cl)::lasts in let rec mk_sign sign = function | (f,n,ar)::oth -> let (sp',_) = check_ind env n ar in if not (sp=sp') then error ("Fixpoints should be on the same " ^ "mutual inductive declaration."); if !check && mem_named_context f (named_context_of_val sign) then error ("Name "^string_of_id f^" already used in the environment"); mk_sign (push_named_context_val (f,None,ar) sign) oth | [] -> List.map (fun (_,_,c) -> mk_goal sign c) all in (mk_sign sign all, sigma) | Cofix (f,others,j) -> let rec check_is_coind env cl = let b = whd_betadeltaiota env sigma cl in match kind_of_term b with | Prod (na,c1,b) -> check_is_coind (push_rel (na,None,c1) env) b | _ -> try let _ = find_coinductive env sigma b in () with Not_found -> error ("All methods must construct elements " ^ "in coinductive types.") in let firsts,lasts = list_chop j others in let all = firsts@(f,cl)::lasts in List.iter (fun (_,c) -> check_is_coind env c) all; let rec mk_sign sign = function | (f,ar)::oth -> (try (let _ = lookup_named_val f sign in error "Name already used in the environment.") with | Not_found -> mk_sign (push_named_context_val (f,None,ar) sign) oth) | [] -> List.map (fun (_,c) -> mk_goal sign c) all in (mk_sign sign all, sigma) | Refine c -> check_meta_variables c; let (sgl,cl') = mk_refgoals sigma goal [] cl c in let sgl = List.rev sgl in (sgl, sigma) (* Conversion rules *) | Convert_concl (cl',_) -> check_typability env sigma cl'; if (not !check) || is_conv_leq env sigma cl' cl then let sg = mk_goal sign cl' in ([sg], sigma) else error "convert-concl rule passed non-converting term" | Convert_hyp (id,copt,ty) -> ([mk_goal (convert_hyp sign sigma (id,copt,ty)) cl], sigma) (* And now the structural rules *) | Thin ids -> let (hyps,concl,nsigma) = clear_hyps sigma ids sign cl in ([mk_goal hyps concl], nsigma) | ThinBody ids -> let clear_aux env id = let env' = remove_hyp_body env sigma id in if !check then recheck_typability (None,id) env' sigma cl; env' in let sign' = named_context_val (List.fold_left clear_aux env ids) in let sg = mk_goal sign' cl in ([sg], sigma) | Move (withdep, hfrom, hto) -> let (left,right,declfrom,toleft) = split_sign hfrom hto (named_context_of_val sign) in let hyps' = move_hyp withdep toleft (left,declfrom,right) hto in ([mk_goal hyps' cl], sigma) | Order ord -> let hyps' = reorder_val_context env sign ord in ([mk_goal hyps' cl], sigma) | Rename (id1,id2) -> if !check & id1 <> id2 && List.mem id2 (ids_of_named_context (named_context_of_val sign)) then error ((string_of_id id2)^" is already used."); let sign' = rename_hyp id1 id2 sign in let cl' = replace_vars [id1,mkVar id2] cl in ([mk_goal sign' cl'], sigma) | Change_evars -> match norm_goal sigma goal with Some ngl -> ([ngl],sigma) | None -> ([goal], sigma) (************************************************************************) (************************************************************************) (* Extracting a proof term from the proof tree *) (* Util *) type variable_proof_status = ProofVar | SectionVar of identifier type proof_variable = name * variable_proof_status let subst_proof_vars = let rec aux p vars = let _,subst = List.fold_left (fun (n,l) var -> let t = match var with | Anonymous,_ -> l | Name id, ProofVar -> (id,mkRel n)::l | Name id, SectionVar id' -> (id,mkVar id')::l in (n+1,t)) (p,[]) vars in replace_vars (List.rev subst) in aux 1 let rec rebind id1 id2 = function | [] -> [Name id2,SectionVar id1] | (na,k as x)::l -> if na = Name id1 then (Name id2,k)::l else let l' = rebind id1 id2 l in if na = Name id2 then (Anonymous,k)::l' else x::l' let add_proof_var id vl = (Name id,ProofVar)::vl let proof_variable_index x = let rec aux n = function | (Name id,ProofVar)::l when x = id -> n | _::l -> aux (n+1) l | [] -> raise Not_found in aux 1 let prim_extractor subfun vl pft = let cl = pft.goal.evar_concl in match pft.ref with | Some (Prim (Intro id), [spf]) -> (match kind_of_term (strip_outer_cast cl) with | Prod (_,ty,_) -> let cty = subst_proof_vars vl ty in mkLambda (Name id, cty, subfun (add_proof_var id vl) spf) | LetIn (_,b,ty,_) -> let cb = subst_proof_vars vl b in let cty = subst_proof_vars vl ty in mkLetIn (Name id, cb, cty, subfun (add_proof_var id vl) spf) | _ -> error "Incomplete proof!") | Some (Prim (Cut (b,_,id,t)),[spf1;spf2]) -> let spf1, spf2 = if b then spf1, spf2 else spf2, spf1 in mkLetIn (Name id,subfun vl spf1,subst_proof_vars vl t, subfun (add_proof_var id vl) spf2) | Some (Prim (FixRule (f,n,others,j)),spfl) -> let firsts,lasts = list_chop j others in let all = Array.of_list (firsts@(f,n,cl)::lasts) in let lcty = Array.map (fun (_,_,ar) -> subst_proof_vars vl ar) all in let names = Array.map (fun (f,_,_) -> Name f) all in let vn = Array.map (fun (_,n,_) -> n-1) all in let newvl = List.fold_left (fun vl (id,_,_) -> add_proof_var id vl) (add_proof_var f vl) others in let lfix = Array.map (subfun newvl) (Array.of_list spfl) in mkFix ((vn,j),(names,lcty,lfix)) | Some (Prim (Cofix (f,others,j)),spfl) -> let firsts,lasts = list_chop j others in let all = Array.of_list (firsts@(f,cl)::lasts) in let lcty = Array.map (fun (_,ar) -> subst_proof_vars vl ar) all in let names = Array.map (fun (f,_) -> Name f) all in let newvl = List.fold_left (fun vl (id,_)-> add_proof_var id vl) (add_proof_var f vl) others in let lfix = Array.map (subfun newvl) (Array.of_list spfl) in mkCoFix (j,(names,lcty,lfix)) | Some (Prim (Refine c),spfl) -> let mvl = collect_meta_variables c in let metamap = List.combine mvl (List.map (subfun vl) spfl) in let cc = subst_proof_vars vl c in plain_instance metamap cc (* Structural and conversion rules do not produce any proof *) | Some (Prim (Convert_concl (t,k)),[pf]) -> if k = DEFAULTcast then subfun vl pf else mkCast (subfun vl pf,k,subst_proof_vars vl cl) | Some (Prim (Convert_hyp _),[pf]) -> subfun vl pf | Some (Prim (Thin _),[pf]) -> (* No need to make ids Anon in vl: subst_proof_vars take the most recent*) subfun vl pf | Some (Prim (ThinBody _),[pf]) -> subfun vl pf | Some (Prim (Move _|Order _),[pf]) -> subfun vl pf | Some (Prim (Rename (id1,id2)),[pf]) -> subfun (rebind id1 id2 vl) pf | Some (Prim Change_evars, [pf]) -> subfun vl pf | Some _ -> anomaly "prim_extractor" | None-> error "prim_extractor handed incomplete proof"