(************************************************************************) (* v * The Coq Proof Assistant / The Coq Development Team *) (* mkLambda (x,t,under_binders (push_rel (x,None,t) env) f (n-1) c) | LetIn (x,b,t,c) -> mkLetIn (x,b,t,under_binders (push_rel (x,Some b,t) env) f (n-1) c) | _ -> assert false let rec complete_conclusion a cs = function | CProdN (loc,bl,c) -> CProdN (loc,bl,complete_conclusion a cs c) | CLetIn (loc,b,t,c) -> CLetIn (loc,b,t,complete_conclusion a cs c) | CHole (loc, k, _, _) -> let (has_no_args,name,params) = a in if not has_no_args then user_err_loc (loc,"", strbrk"Cannot infer the non constant arguments of the conclusion of " ++ pr_id cs ++ str "."); let args = List.map (fun id -> CRef(Ident(loc,id),None)) params in CAppExpl (loc,(None,Ident(loc,name),None),List.rev args) | c -> c (* Commands of the interface *) (* 1| Constant definitions *) let red_constant_entry n ce = function | None -> ce | Some red -> let proof_out = ce.const_entry_body in let env = Global.env () in { ce with const_entry_body = Future.chain ~greedy:true ~pure:true proof_out (fun ((body,ctx),eff) -> (under_binders env (fst (reduction_of_red_expr env red)) n body,ctx),eff) } let interp_definition pl bl p red_option c ctypopt = let env = Global.env() in let ctx = Evd.make_evar_universe_context env pl in let evdref = ref (Evd.from_ctx ctx) in let impls, ((env_bl, ctx), imps1) = interp_context_evars env evdref bl in let nb_args = List.length ctx in let imps,ce = match ctypopt with None -> let subst = evd_comb0 Evd.nf_univ_variables evdref in let ctx = map_rel_context (Vars.subst_univs_constr subst) ctx in let env_bl = push_rel_context ctx env in let c, imps2 = interp_constr_evars_impls ~impls env_bl evdref c in let nf,subst = Evarutil.e_nf_evars_and_universes evdref in let body = nf (it_mkLambda_or_LetIn c ctx) in let vars = Universes.universes_of_constr body in let evd = Evd.restrict_universe_context !evdref vars in let uctx = Evd.universe_context ?names:pl evd in imps1@(Impargs.lift_implicits nb_args imps2), definition_entry ~univs:uctx ~poly:p body | Some ctyp -> let ty, impsty = interp_type_evars_impls ~impls env_bl evdref ctyp in let subst = evd_comb0 Evd.nf_univ_variables evdref in let ctx = map_rel_context (Vars.subst_univs_constr subst) ctx in let env_bl = push_rel_context ctx env in let c, imps2 = interp_casted_constr_evars_impls ~impls env_bl evdref c ty in let nf, subst = Evarutil.e_nf_evars_and_universes evdref in let body = nf (it_mkLambda_or_LetIn c ctx) in let typ = nf (it_mkProd_or_LetIn ty ctx) in let beq b1 b2 = if b1 then b2 else not b2 in let impl_eq (x,y,z) (x',y',z') = beq x x' && beq y y' && beq z z' in (* Check that all implicit arguments inferable from the term are inferable from the type *) let chk (key,va) = impl_eq (List.assoc_f Pervasives.(=) key impsty) va (* FIXME *) in if not (try List.for_all chk imps2 with Not_found -> false) then msg_warning (strbrk "Implicit arguments declaration relies on type." ++ spc () ++ strbrk "The term declares more implicits than the type here."); let vars = Univ.LSet.union (Universes.universes_of_constr body) (Universes.universes_of_constr typ) in let ctx = Evd.restrict_universe_context !evdref vars in let uctx = Evd.universe_context ?names:pl ctx in imps1@(Impargs.lift_implicits nb_args impsty), definition_entry ~types:typ ~poly:p ~univs:uctx body in red_constant_entry (rel_context_length ctx) ce red_option, !evdref, imps let check_definition (ce, evd, imps) = check_evars_are_solved (Global.env ()) evd (Evd.empty,evd); ce let get_locality id = function | Discharge -> (** If a Let is defined outside a section, then we consider it as a local definition *) let msg = pr_id id ++ strbrk " is declared as a local definition" in let () = msg_warning msg in true | Local -> true | Global -> false let declare_global_definition ident ce local k imps = let local = get_locality ident local in let kn = declare_constant ident ~local (DefinitionEntry ce, IsDefinition k) in let gr = ConstRef kn in let () = maybe_declare_manual_implicits false gr imps in let () = definition_message ident in gr let declare_definition_hook = ref ignore let set_declare_definition_hook = (:=) declare_definition_hook let get_declare_definition_hook () = !declare_definition_hook let declare_definition ident (local, p, k) ce imps hook = let () = !declare_definition_hook ce in let r = match local with | Discharge when Lib.sections_are_opened () -> let c = SectionLocalDef ce in let _ = declare_variable ident (Lib.cwd(), c, IsDefinition k) in let () = definition_message ident in let gr = VarRef ident in let () = maybe_declare_manual_implicits false gr imps in let () = if Pfedit.refining () then let msg = strbrk "Section definition " ++ pr_id ident ++ strbrk " is not visible from current goals" in msg_warning msg in gr | Discharge | Local | Global -> declare_global_definition ident ce local k imps in Lemmas.call_hook (Future.fix_exn_of ce.Entries.const_entry_body) hook local r let _ = Obligations.declare_definition_ref := declare_definition let do_definition ident k pl bl red_option c ctypopt hook = let (ce, evd, imps as def) = interp_definition pl bl (pi2 k) red_option c ctypopt in if Flags.is_program_mode () then let env = Global.env () in let (c,ctx), sideff = Future.force ce.const_entry_body in assert(Declareops.side_effects_is_empty sideff); assert(Univ.ContextSet.is_empty ctx); let typ = match ce.const_entry_type with | Some t -> t | None -> Retyping.get_type_of env evd c in Obligations.check_evars env evd; let obls, _, c, cty = Obligations.eterm_obligations env ident evd 0 c typ in let ctx = Evd.evar_universe_context evd in ignore(Obligations.add_definition ident ~term:c cty ctx ~implicits:imps ~kind:k ~hook obls) else let ce = check_definition def in ignore(declare_definition ident k ce imps (Lemmas.mk_hook (fun l r -> Lemmas.call_hook (fun exn -> exn) hook l r;r))) (* 2| Variable/Hypothesis/Parameter/Axiom declarations *) let declare_assumption is_coe (local,p,kind) (c,ctx) imps impl nl (_,ident) = match local with | Discharge when Lib.sections_are_opened () -> let decl = (Lib.cwd(), SectionLocalAssum ((c,ctx),p,impl), IsAssumption kind) in let _ = declare_variable ident decl in let () = assumption_message ident in let () = if is_verbose () && Pfedit.refining () then msg_warning (str"Variable" ++ spc () ++ pr_id ident ++ strbrk " is not visible from current goals") in let r = VarRef ident in let () = Typeclasses.declare_instance None true r in let () = if is_coe then Class.try_add_new_coercion r ~local:true false in (r,Univ.Instance.empty,true) | Global | Local | Discharge -> let local = get_locality ident local in let inl = match nl with | NoInline -> None | DefaultInline -> Some (Flags.get_inline_level()) | InlineAt i -> Some i in let ctx = Univ.ContextSet.to_context ctx in let decl = (ParameterEntry (None,p,(c,ctx),inl), IsAssumption kind) in let kn = declare_constant ident ~local decl in let gr = ConstRef kn in let () = maybe_declare_manual_implicits false gr imps in let () = assumption_message ident in let () = Typeclasses.declare_instance None false gr in let () = if is_coe then Class.try_add_new_coercion gr local p in let inst = if p (* polymorphic *) then Univ.UContext.instance ctx else Univ.Instance.empty in (gr,inst,Lib.is_modtype_strict ()) let interp_assumption evdref env impls bl c = let c = prod_constr_expr c bl in let ty, impls = interp_type_evars_impls env evdref ~impls c in let evd, nf = nf_evars_and_universes !evdref in let ctx = Evd.universe_context_set evd in ((nf ty, ctx), impls) let declare_assumptions idl is_coe k c imps impl_is_on nl = let refs, status = List.fold_left (fun (refs,status) id -> let ref',u',status' = declare_assumption is_coe k c imps impl_is_on nl id in (ref',u')::refs, status' && status) ([],true) idl in List.rev refs, status let do_assumptions (_, poly, _ as kind) nl l = let env = Global.env () in let evdref = ref (Evd.from_env env) in let l = if poly then (* Separate declarations so that A B : Type puts A and B in different levels. *) List.fold_right (fun (is_coe,(idl,c)) acc -> List.fold_right (fun id acc -> (is_coe, ([id], c)) :: acc) idl acc) l [] else l in let _,l = List.fold_map (fun (env,ienv) (is_coe,(idl,c)) -> let (t,ctx),imps = interp_assumption evdref env ienv [] c in let env = push_named_context (List.map (fun (_,id) -> (id,None,t)) idl) env in let ienv = List.fold_right (fun (_,id) ienv -> let impls = compute_internalization_data env Variable t imps in Id.Map.add id impls ienv) idl ienv in ((env,ienv),((is_coe,idl),t,(ctx,imps)))) (env,empty_internalization_env) l in let evd = solve_remaining_evars all_and_fail_flags env !evdref (Evd.empty,!evdref) in let l = List.map (on_pi2 (nf_evar evd)) l in snd (List.fold_left (fun (subst,status) ((is_coe,idl),t,(ctx,imps)) -> let t = replace_vars subst t in let (refs,status') = declare_assumptions idl is_coe kind (t,ctx) imps false nl in let subst' = List.map2 (fun (_,id) (c,u) -> (id,Universes.constr_of_global_univ (c,u))) idl refs in (subst'@subst, status' && status)) ([],true) l) (* 3a| Elimination schemes for mutual inductive definitions *) (* 3b| Mutual inductive definitions *) let push_types env idl tl = List.fold_left2 (fun env id t -> Environ.push_rel (Name id,None,t) env) env idl tl type structured_one_inductive_expr = { ind_name : Id.t; ind_univs : lident list option; ind_arity : constr_expr; ind_lc : (Id.t * constr_expr) list } type structured_inductive_expr = local_binder list * structured_one_inductive_expr list let minductive_message warn = function | [] -> error "No inductive definition." | [x] -> (pr_id x ++ str " is defined" ++ if warn then str " as a non-primitive record" else mt()) | l -> hov 0 (prlist_with_sep pr_comma pr_id l ++ spc () ++ str "are defined") let check_all_names_different indl = let ind_names = List.map (fun ind -> ind.ind_name) indl in let cstr_names = List.map_append (fun ind -> List.map fst ind.ind_lc) indl in let l = List.duplicates Id.equal ind_names in let () = match l with | [] -> () | t :: _ -> raise (InductiveError (SameNamesTypes t)) in let l = List.duplicates Id.equal cstr_names in let () = match l with | [] -> () | c :: _ -> raise (InductiveError (SameNamesConstructors (List.hd l))) in let l = List.intersect Id.equal ind_names cstr_names in match l with | [] -> () | _ -> raise (InductiveError (SameNamesOverlap l)) let mk_mltype_data evdref env assums arity indname = let is_ml_type = is_sort env !evdref arity in (is_ml_type,indname,assums) let prepare_param = function | (na,None,t) -> out_name na, LocalAssum t | (na,Some b,_) -> out_name na, LocalDef b (** Make the arity conclusion flexible to avoid generating an upper bound universe now, only if the universe does not appear anywhere else. This is really a hack to stay compatible with the semantics of template polymorphic inductives which are recognized when a "Type" appears at the end of the conlusion in the source syntax. *) let rec check_anonymous_type ind = let open Glob_term in match ind with | GSort (_, GType []) -> true | GProd (_, _, _, _, e) | GLetIn (_, _, _, e) | GLambda (_, _, _, _, e) | GApp (_, e, _) | GCast (_, e, _) -> check_anonymous_type e | _ -> false let make_conclusion_flexible evdref ty poly = if poly && isArity ty then let _, concl = destArity ty in match concl with | Type u -> (match Univ.universe_level u with | Some u -> evdref := Evd.make_flexible_variable !evdref true u | None -> ()) | _ -> () else () let is_impredicative env u = u = Prop Null || (is_impredicative_set env && u = Prop Pos) let interp_ind_arity env evdref ind = let c = intern_gen IsType env ind.ind_arity in let imps = Implicit_quantifiers.implicits_of_glob_constr ~with_products:true c in let t, impls = understand_tcc_evars env evdref ~expected_type:IsType c, imps in let pseudo_poly = check_anonymous_type c in let () = if not (Reduction.is_arity env t) then user_err_loc (constr_loc ind.ind_arity, "", str "Not an arity") in t, pseudo_poly, impls let interp_cstrs evdref env impls mldata arity ind = let cnames,ctyps = List.split ind.ind_lc in (* Complete conclusions of constructor types if given in ML-style syntax *) let ctyps' = List.map2 (complete_conclusion mldata) cnames ctyps in (* Interpret the constructor types *) let ctyps'', cimpls = List.split (List.map (interp_type_evars_impls evdref env ~impls) ctyps') in (cnames, ctyps'', cimpls) let sign_level env evd sign = fst (List.fold_right (fun (_,b,t as d) (lev,env) -> match b with | Some _ -> (lev, push_rel d env) | None -> let s = destSort (Reduction.whd_betadeltaiota env (nf_evar evd (Retyping.get_type_of env evd t))) in let u = univ_of_sort s in (Univ.sup u lev, push_rel d env)) sign (Univ.type0m_univ,env)) let sup_list min = List.fold_left Univ.sup min let extract_level env evd min tys = let sorts = List.map (fun ty -> let ctx, concl = Reduction.dest_prod_assum env ty in sign_level env evd ((Anonymous, None, concl) :: ctx)) tys in sup_list min sorts let is_flexible_sort evd u = match Univ.Universe.level u with | Some l -> Evd.is_flexible_level evd l | None -> false let inductive_levels env evdref poly arities inds = let destarities = List.map (fun x -> x, Reduction.dest_arity env x) arities in let levels = List.map (fun (x,(ctx,a)) -> if a = Prop Null then None else Some (univ_of_sort a)) destarities in let cstrs_levels, min_levels, sizes = CList.split3 (List.map2 (fun (_,tys,_) (arity,(ctx,du)) -> let len = List.length tys in let minlev = Sorts.univ_of_sort du in let minlev = if len > 1 && not (is_impredicative env du) then Univ.sup minlev Univ.type0_univ else minlev in let minlev = (** Indices contribute. *) if Indtypes.is_indices_matter () && List.length ctx > 0 then ( let ilev = sign_level env !evdref ctx in Univ.sup ilev minlev) else minlev in let clev = extract_level env !evdref minlev tys in (clev, minlev, len)) inds destarities) in (* Take the transitive closure of the system of constructors *) (* level constraints and remove the recursive dependencies *) let levels' = Universes.solve_constraints_system (Array.of_list levels) (Array.of_list cstrs_levels) (Array.of_list min_levels) in let evd, arities = CList.fold_left3 (fun (evd, arities) cu (arity,(ctx,du)) len -> if is_impredicative env du then (** Any product is allowed here. *) evd, arity :: arities else (** If in a predicative sort, or asked to infer the type, we take the max of: - indices (if in indices-matter mode) - constructors - Type(1) if there is more than 1 constructor *) (** Constructors contribute. *) let evd = if Sorts.is_set du then if not (Evd.check_leq evd cu Univ.type0_univ) then raise (Indtypes.InductiveError Indtypes.LargeNonPropInductiveNotInType) else evd else evd (* Evd.set_leq_sort env evd (Type cu) du *) in let evd = if len >= 2 && Univ.is_type0m_univ cu then (** "Polymorphic" type constraint and more than one constructor, should not land in Prop. Add constraint only if it would land in Prop directly (no informative arguments as well). *) Evd.set_leq_sort env evd (Prop Pos) du else evd in (* let arity = it_mkProd_or_LetIn (mkType cu) ctx in *\) *) let duu = Sorts.univ_of_sort du in let evd = if not (Univ.is_small_univ duu) && Evd.check_eq evd cu duu then if is_flexible_sort evd duu then Evd.set_eq_sort env evd (Prop Null) du else evd else Evd.set_eq_sort env evd (Type cu) du in (evd, arity :: arities)) (!evdref,[]) (Array.to_list levels') destarities sizes in evdref := evd; List.rev arities let check_named (loc, na) = match na with | Name _ -> () | Anonymous -> let msg = str "Parameters must be named." in user_err_loc (loc, "", msg) let check_param = function | LocalRawDef (na, _) -> check_named na | LocalRawAssum (nas, Default _, _) -> List.iter check_named nas | LocalRawAssum (nas, Generalized _, _) -> () let interp_mutual_inductive (paramsl,indl) notations poly prv finite = check_all_names_different indl; List.iter check_param paramsl; let env0 = Global.env() in let evdref = ref Evd.(from_env env0) in let _, ((env_params, ctx_params), userimpls) = interp_context_evars env0 evdref paramsl in let indnames = List.map (fun ind -> ind.ind_name) indl in let pl = (List.hd indl).ind_univs in (* Names of parameters as arguments of the inductive type (defs removed) *) let assums = List.filter(fun (_,b,_) -> Option.is_empty b) ctx_params in let params = List.map (fun (na,_,_) -> out_name na) assums in (* Interpret the arities *) let arities = List.map (interp_ind_arity env_params evdref) indl in let fullarities = List.map (fun (c, _, _) -> it_mkProd_or_LetIn c ctx_params) arities in let env_ar = push_types env0 indnames fullarities in let env_ar_params = push_rel_context ctx_params env_ar in (* Compute interpretation metadatas *) let indimpls = List.map (fun (_, _, impls) -> userimpls @ lift_implicits (rel_context_nhyps ctx_params) impls) arities in let arities = List.map pi1 arities and aritypoly = List.map pi2 arities in let impls = compute_internalization_env env0 (Inductive params) indnames fullarities indimpls in let mldatas = List.map2 (mk_mltype_data evdref env_params params) arities indnames in let constructors = Metasyntax.with_syntax_protection (fun () -> (* Temporary declaration of notations and scopes *) List.iter (Metasyntax.set_notation_for_interpretation impls) notations; (* Interpret the constructor types *) List.map3 (interp_cstrs env_ar_params evdref impls) mldatas arities indl) () in (* Try further to solve evars, and instantiate them *) let sigma = solve_remaining_evars all_and_fail_flags env_params !evdref (Evd.empty,!evdref) in evdref := sigma; (* Compute renewed arities *) let nf,_ = e_nf_evars_and_universes evdref in let arities = List.map nf arities in let constructors = List.map (fun (idl,cl,impsl) -> (idl,List.map nf cl,impsl)) constructors in let _ = List.iter2 (fun ty poly -> make_conclusion_flexible evdref ty poly) arities aritypoly in let arities = inductive_levels env_ar_params evdref poly arities constructors in let nf',_ = e_nf_evars_and_universes evdref in let nf x = nf' (nf x) in let arities = List.map nf' arities in let constructors = List.map (fun (idl,cl,impsl) -> (idl,List.map nf' cl,impsl)) constructors in let ctx_params = map_rel_context nf ctx_params in let evd = !evdref in let uctx = Evd.universe_context ?names:pl evd in List.iter (check_evars env_params Evd.empty evd) arities; iter_rel_context (check_evars env0 Evd.empty evd) ctx_params; List.iter (fun (_,ctyps,_) -> List.iter (check_evars env_ar_params Evd.empty evd) ctyps) constructors; (* Build the inductive entries *) let entries = List.map4 (fun ind arity template (cnames,ctypes,cimpls) -> { mind_entry_typename = ind.ind_name; mind_entry_arity = arity; mind_entry_template = template; mind_entry_consnames = cnames; mind_entry_lc = ctypes }) indl arities aritypoly constructors in let impls = let len = rel_context_nhyps ctx_params in List.map2 (fun indimpls (_,_,cimpls) -> indimpls, List.map (fun impls -> userimpls @ (lift_implicits len impls)) cimpls) indimpls constructors in (* Build the mutual inductive entry *) { mind_entry_params = List.map prepare_param ctx_params; mind_entry_record = None; mind_entry_finite = finite; mind_entry_inds = entries; mind_entry_polymorphic = poly; mind_entry_private = if prv then Some false else None; mind_entry_universes = uctx }, impls (* Very syntactical equality *) let eq_local_binders bl1 bl2 = List.equal local_binder_eq bl1 bl2 let extract_coercions indl = let mkqid (_,((_,id),_)) = qualid_of_ident id in let extract lc = List.filter (fun (iscoe,_) -> iscoe) lc in List.map mkqid (List.flatten(List.map (fun (_,_,_,lc) -> extract lc) indl)) let extract_params indl = let paramsl = List.map (fun (_,params,_,_) -> params) indl in match paramsl with | [] -> anomaly (Pp.str "empty list of inductive types") | params::paramsl -> if not (List.for_all (eq_local_binders params) paramsl) then error "Parameters should be syntactically the same for each inductive type."; params let extract_inductive indl = List.map (fun (((_,indname),pl),_,ar,lc) -> { ind_name = indname; ind_univs = pl; ind_arity = Option.cata (fun x -> x) (CSort (Loc.ghost,GType [])) ar; ind_lc = List.map (fun (_,((_,id),t)) -> (id,t)) lc }) indl let extract_mutual_inductive_declaration_components indl = let indl,ntnl = List.split indl in let params = extract_params indl in let coes = extract_coercions indl in let indl = extract_inductive indl in (params,indl), coes, List.flatten ntnl let is_recursive mie = let rec is_recursive_constructor lift typ = match Term.kind_of_term typ with | Prod (_,arg,rest) -> Termops.dependent (mkRel lift) arg || is_recursive_constructor (lift+1) rest | LetIn (na,b,t,rest) -> is_recursive_constructor (lift+1) rest | _ -> false in match mie.mind_entry_inds with | [ind] -> let nparams = List.length mie.mind_entry_params in List.exists (fun t -> is_recursive_constructor (nparams+1) t) ind.mind_entry_lc | _ -> false let declare_mutual_inductive_with_eliminations mie impls = (* spiwack: raises an error if the structure is supposed to be non-recursive, but isn't *) begin match mie.mind_entry_finite with | BiFinite when is_recursive mie -> if Option.has_some mie.mind_entry_record then error "Records declared with the keywords Record or Structure cannot be recursive. You can, however, define recursive records using the Inductive or CoInductive command." else error ("Types declared with the keyword Variant cannot be recursive. Recursive types are defined with the Inductive and CoInductive command.") | _ -> () end; let names = List.map (fun e -> e.mind_entry_typename) mie.mind_entry_inds in let (_, kn), prim = declare_mind mie in let mind = Global.mind_of_delta_kn kn in List.iteri (fun i (indimpls, constrimpls) -> let ind = (mind,i) in maybe_declare_manual_implicits false (IndRef ind) indimpls; List.iteri (fun j impls -> maybe_declare_manual_implicits false (ConstructRef (ind, succ j)) impls) constrimpls) impls; let warn_prim = match mie.mind_entry_record with Some (Some _) -> not prim | _ -> false in if_verbose msg_info (minductive_message warn_prim names); if mie.mind_entry_private == None then declare_default_schemes mind; mind type one_inductive_impls = Impargs.manual_explicitation list (* for inds *)* Impargs.manual_explicitation list list (* for constrs *) let do_mutual_inductive indl poly prv finite = let indl,coes,ntns = extract_mutual_inductive_declaration_components indl in (* Interpret the types *) let mie,impls = interp_mutual_inductive indl ntns poly prv finite in (* Declare the mutual inductive block with its associated schemes *) ignore (declare_mutual_inductive_with_eliminations mie impls); (* Declare the possible notations of inductive types *) List.iter Metasyntax.add_notation_interpretation ntns; (* Declare the coercions *) List.iter (fun qid -> Class.try_add_new_coercion (locate qid) false poly) coes (* 3c| Fixpoints and co-fixpoints *) (* An (unoptimized) function that maps preorders to partial orders... Input: a list of associations (x,[y1;...;yn]), all yi distincts and different of x, meaning x<=y1, ..., x<=yn Output: a list of associations (x,Inr [y1;...;yn]), collecting all distincts yi greater than x, _or_, (x, Inl y) meaning that x is in the same class as y (in which case, x occurs nowhere else in the association map) partial_order : ('a * 'a list) list -> ('a * ('a,'a list) union) list *) let rec partial_order cmp = function | [] -> [] | (x,xge)::rest -> let rec browse res xge' = function | [] -> let res = List.map (function | (z, Inr zge) when List.mem_f cmp x zge -> (z, Inr (List.union cmp zge xge')) | r -> r) res in (x,Inr xge')::res | y::xge -> let rec link y = try match List.assoc_f cmp y res with | Inl z -> link z | Inr yge -> if List.mem_f cmp x yge then let res = List.remove_assoc_f cmp y res in let res = List.map (function | (z, Inl t) -> if cmp t y then (z, Inl x) else (z, Inl t) | (z, Inr zge) -> if List.mem_f cmp y zge then (z, Inr (List.add_set cmp x (List.remove cmp y zge))) else (z, Inr zge)) res in browse ((y,Inl x)::res) xge' (List.union cmp xge (List.remove cmp x yge)) else browse res (List.add_set cmp y (List.union cmp xge' yge)) xge with Not_found -> browse res (List.add_set cmp y xge') xge in link y in browse (partial_order cmp rest) [] xge let non_full_mutual_message x xge y yge isfix rest = let reason = if Id.List.mem x yge then pr_id y ++ str " depends on " ++ pr_id x ++ str " but not conversely" else if Id.List.mem y xge then pr_id x ++ str " depends on " ++ pr_id y ++ str " but not conversely" else pr_id y ++ str " and " ++ pr_id x ++ str " are not mutually dependent" in let e = if List.is_empty rest then reason else str "e.g., " ++ reason in let k = if isfix then "fixpoint" else "cofixpoint" in let w = if isfix then str "Well-foundedness check may fail unexpectedly." ++ fnl() else mt () in str "Not a fully mutually defined " ++ str k ++ fnl () ++ str "(" ++ e ++ str ")." ++ fnl () ++ w let check_mutuality env isfix fixl = let names = List.map fst fixl in let preorder = List.map (fun (id,def) -> (id, List.filter (fun id' -> not (Id.equal id id') && occur_var env id' def) names)) fixl in let po = partial_order Id.equal preorder in match List.filter (function (_,Inr _) -> true | _ -> false) po with | (x,Inr xge)::(y,Inr yge)::rest -> msg_warning (non_full_mutual_message x xge y yge isfix rest) | _ -> () type structured_fixpoint_expr = { fix_name : Id.t; fix_univs : lident list option; fix_annot : Id.t Loc.located option; fix_binders : local_binder list; fix_body : constr_expr option; fix_type : constr_expr } let interp_fix_context env evdref isfix fix = let before, after = if isfix then split_at_annot fix.fix_binders fix.fix_annot else [], fix.fix_binders in let impl_env, ((env', ctx), imps) = interp_context_evars env evdref before in let impl_env', ((env'', ctx'), imps') = interp_context_evars ~impl_env ~shift:(List.length before) env' evdref after in let annot = Option.map (fun _ -> List.length (assums_of_rel_context ctx)) fix.fix_annot in ((env'', ctx' @ ctx), (impl_env',imps @ imps'), annot) let interp_fix_ccl evdref impls (env,_) fix = interp_type_evars_impls ~impls env evdref fix.fix_type let interp_fix_body env_rec evdref impls (_,ctx) fix ccl = Option.map (fun body -> let env = push_rel_context ctx env_rec in let body = interp_casted_constr_evars env evdref ~impls body ccl in it_mkLambda_or_LetIn body ctx) fix.fix_body let build_fix_type (_,ctx) ccl = it_mkProd_or_LetIn ccl ctx let declare_fix ?(opaque = false) (_,poly,_ as kind) ctx f ((def,_),eff) t imps = let ce = definition_entry ~opaque ~types:t ~poly ~univs:ctx ~eff def in declare_definition f kind ce imps (Lemmas.mk_hook (fun _ r -> r)) let _ = Obligations.declare_fix_ref := declare_fix let prepare_recursive_declaration fixnames fixtypes fixdefs = let defs = List.map (subst_vars (List.rev fixnames)) fixdefs in let names = List.map (fun id -> Name id) fixnames in (Array.of_list names, Array.of_list fixtypes, Array.of_list defs) (* Jump over let-bindings. *) let compute_possible_guardness_evidences (ids,_,na) = match na with | Some i -> [i] | None -> (* If recursive argument was not given by user, we try all args. An earlier approach was to look only for inductive arguments, but doing it properly involves delta-reduction, and it finally doesn't seem to worth the effort (except for huge mutual fixpoints ?) *) List.interval 0 (List.length ids - 1) type recursive_preentry = Id.t list * constr option list * types list (* Wellfounded definition *) open Coqlib let contrib_name = "Program" let subtac_dir = [contrib_name] let fixsub_module = subtac_dir @ ["Wf"] let tactics_module = subtac_dir @ ["Tactics"] let init_reference dir s () = Coqlib.gen_reference "Command" dir s let init_constant dir s () = Coqlib.gen_constant "Command" dir s let make_ref l s = init_reference l s let fix_proto = init_constant tactics_module "fix_proto" let fix_sub_ref = make_ref fixsub_module "Fix_sub" let measure_on_R_ref = make_ref fixsub_module "MR" let well_founded = init_constant ["Init"; "Wf"] "well_founded" let mkSubset name typ prop = mkApp (Universes.constr_of_global (delayed_force build_sigma).typ, [| typ; mkLambda (name, typ, prop) |]) let sigT = Lazy.lazy_from_fun build_sigma_type let make_qref s = Qualid (Loc.ghost, qualid_of_string s) let lt_ref = make_qref "Init.Peano.lt" let rec telescope = function | [] -> assert false | [(n, None, t)] -> t, [n, Some (mkRel 1), t], mkRel 1 | (n, None, t) :: tl -> let ty, tys, (k, constr) = List.fold_left (fun (ty, tys, (k, constr)) (n, b, t) -> let pred = mkLambda (n, t, ty) in let ty = Universes.constr_of_global (Lazy.force sigT).typ in let intro = Universes.constr_of_global (Lazy.force sigT).intro in let sigty = mkApp (ty, [|t; pred|]) in let intro = mkApp (intro, [|lift k t; lift k pred; mkRel k; constr|]) in (sigty, pred :: tys, (succ k, intro))) (t, [], (2, mkRel 1)) tl in let (last, subst) = List.fold_right2 (fun pred (n, b, t) (prev, subst) -> let p1 = Universes.constr_of_global (Lazy.force sigT).proj1 in let p2 = Universes.constr_of_global (Lazy.force sigT).proj2 in let proj1 = applistc p1 [t; pred; prev] in let proj2 = applistc p2 [t; pred; prev] in (lift 1 proj2, (n, Some proj1, t) :: subst)) (List.rev tys) tl (mkRel 1, []) in ty, ((n, Some last, t) :: subst), constr | (n, Some b, t) :: tl -> let ty, subst, term = telescope tl in ty, ((n, Some b, t) :: subst), lift 1 term let nf_evar_context sigma ctx = List.map (fun (n, b, t) -> (n, Option.map (Evarutil.nf_evar sigma) b, Evarutil.nf_evar sigma t)) ctx let build_wellfounded (recname,n,bl,arityc,body) r measure notation = Coqlib.check_required_library ["Coq";"Program";"Wf"]; let env = Global.env() in let evdref = ref (Evd.from_env env) in let _, ((env', binders_rel), impls) = interp_context_evars env evdref bl in let len = List.length binders_rel in let top_env = push_rel_context binders_rel env in let top_arity = interp_type_evars top_env evdref arityc in let full_arity = it_mkProd_or_LetIn top_arity binders_rel in let argtyp, letbinders, make = telescope binders_rel in let argname = Id.of_string "recarg" in let arg = (Name argname, None, argtyp) in let binders = letbinders @ [arg] in let binders_env = push_rel_context binders_rel env in let rel, _ = interp_constr_evars_impls env evdref r in let () = check_evars_are_solved env !evdref (Evd.empty,!evdref) in let relty = Typing.unsafe_type_of env !evdref rel in let relargty = let error () = user_err_loc (constr_loc r, "Command.build_wellfounded", Printer.pr_constr_env env !evdref rel ++ str " is not an homogeneous binary relation.") in try let ctx, ar = Reductionops.splay_prod_n env !evdref 2 relty in match ctx, kind_of_term ar with | [(_, None, t); (_, None, u)], Sort (Prop Null) when Reductionops.is_conv env !evdref t u -> t | _, _ -> error () with e when Errors.noncritical e -> error () in let measure = interp_casted_constr_evars binders_env evdref measure relargty in let wf_rel, wf_rel_fun, measure_fn = let measure_body, measure = it_mkLambda_or_LetIn measure letbinders, it_mkLambda_or_LetIn measure binders in let comb = Universes.constr_of_global (delayed_force measure_on_R_ref) in let wf_rel = mkApp (comb, [| argtyp; relargty; rel; measure |]) in let wf_rel_fun x y = mkApp (rel, [| subst1 x measure_body; subst1 y measure_body |]) in wf_rel, wf_rel_fun, measure in let wf_proof = mkApp (delayed_force well_founded, [| argtyp ; wf_rel |]) in let argid' = Id.of_string (Id.to_string argname ^ "'") in let wfarg len = (Name argid', None, mkSubset (Name argid') argtyp (wf_rel_fun (mkRel 1) (mkRel (len + 1)))) in let intern_bl = wfarg 1 :: [arg] in let _intern_env = push_rel_context intern_bl env in let proj = (*FIXME*)Universes.constr_of_global (delayed_force build_sigma).Coqlib.proj1 in let wfargpred = mkLambda (Name argid', argtyp, wf_rel_fun (mkRel 1) (mkRel 3)) in let projection = (* in wfarg :: arg :: before *) mkApp (proj, [| argtyp ; wfargpred ; mkRel 1 |]) in let top_arity_let = it_mkLambda_or_LetIn top_arity letbinders in let intern_arity = substl [projection] top_arity_let in (* substitute the projection of wfarg for something, now intern_arity is in wfarg :: arg *) let intern_fun_arity_prod = it_mkProd_or_LetIn intern_arity [wfarg 1] in let intern_fun_binder = (Name (add_suffix recname "'"), None, intern_fun_arity_prod) in let curry_fun = let wfpred = mkLambda (Name argid', argtyp, wf_rel_fun (mkRel 1) (mkRel (2 * len + 4))) in let intro = (*FIXME*)Universes.constr_of_global (delayed_force build_sigma).Coqlib.intro in let arg = mkApp (intro, [| argtyp; wfpred; lift 1 make; mkRel 1 |]) in let app = mkApp (mkRel (2 * len + 2 (* recproof + orig binders + current binders *)), [| arg |]) in let rcurry = mkApp (rel, [| measure; lift len measure |]) in let lam = (Name (Id.of_string "recproof"), None, rcurry) in let body = it_mkLambda_or_LetIn app (lam :: binders_rel) in let ty = it_mkProd_or_LetIn (lift 1 top_arity) (lam :: binders_rel) in (Name recname, Some body, ty) in let fun_bl = intern_fun_binder :: [arg] in let lift_lets = Termops.lift_rel_context 1 letbinders in let intern_body = let ctx = (Name recname, None, pi3 curry_fun) :: binders_rel in let (r, l, impls, scopes) = Constrintern.compute_internalization_data env Constrintern.Recursive full_arity impls in let newimpls = Id.Map.singleton recname (r, l, impls @ [(Some (Id.of_string "recproof", Impargs.Manual, (true, false)))], scopes @ [None]) in interp_casted_constr_evars (push_rel_context ctx env) evdref ~impls:newimpls body (lift 1 top_arity) in let intern_body_lam = it_mkLambda_or_LetIn intern_body (curry_fun :: lift_lets @ fun_bl) in let prop = mkLambda (Name argname, argtyp, top_arity_let) in let def = mkApp (Universes.constr_of_global (delayed_force fix_sub_ref), [| argtyp ; wf_rel ; Evarutil.e_new_evar env evdref ~src:(Loc.ghost, Evar_kinds.QuestionMark (Evar_kinds.Define false)) wf_proof; prop |]) in let def = Typing.solve_evars env evdref def in let _ = evdref := Evarutil.nf_evar_map !evdref in let def = mkApp (def, [|intern_body_lam|]) in let binders_rel = nf_evar_context !evdref binders_rel in let binders = nf_evar_context !evdref binders in let top_arity = Evarutil.nf_evar !evdref top_arity in let hook, recname, typ = if List.length binders_rel > 1 then let name = add_suffix recname "_func" in let hook l gr = let body = it_mkLambda_or_LetIn (mkApp (Universes.constr_of_global gr, [|make|])) binders_rel in let ty = it_mkProd_or_LetIn top_arity binders_rel in let univs = Evd.universe_context !evdref in (*FIXME poly? *) let ce = definition_entry ~types:ty ~univs (Evarutil.nf_evar !evdref body) in (** FIXME: include locality *) let c = Declare.declare_constant recname (DefinitionEntry ce, IsDefinition Definition) in let gr = ConstRef c in if Impargs.is_implicit_args () || not (List.is_empty impls) then Impargs.declare_manual_implicits false gr [impls] in let typ = it_mkProd_or_LetIn top_arity binders in hook, name, typ else let typ = it_mkProd_or_LetIn top_arity binders_rel in let hook l gr = if Impargs.is_implicit_args () || not (List.is_empty impls) then Impargs.declare_manual_implicits false gr [impls] in hook, recname, typ in let hook = Lemmas.mk_hook hook in let fullcoqc = Evarutil.nf_evar !evdref def in let fullctyp = Evarutil.nf_evar !evdref typ in Obligations.check_evars env !evdref; let evars, _, evars_def, evars_typ = Obligations.eterm_obligations env recname !evdref 0 fullcoqc fullctyp in let ctx = Evd.evar_universe_context !evdref in ignore(Obligations.add_definition recname ~term:evars_def evars_typ ctx evars ~hook) let interp_recursive isfix fixl notations = let env = Global.env() in let fixnames = List.map (fun fix -> fix.fix_name) fixl in (* Interp arities allowing for unresolved types *) let evdref = ref (Evd.from_env env) in let fixctxs, fiximppairs, fixannots = List.split3 (List.map (interp_fix_context env evdref isfix) fixl) in let fixctximpenvs, fixctximps = List.split fiximppairs in let fixccls,fixcclimps = List.split (List.map3 (interp_fix_ccl evdref) fixctximpenvs fixctxs fixl) in let fixtypes = List.map2 build_fix_type fixctxs fixccls in let fixtypes = List.map (nf_evar !evdref) fixtypes in let fiximps = List.map3 (fun ctximps cclimps (_,ctx) -> ctximps@(Impargs.lift_implicits (List.length ctx) cclimps)) fixctximps fixcclimps fixctxs in let rec_sign = List.fold_left2 (fun env' id t -> if Flags.is_program_mode () then let sort = Evarutil.evd_comb1 (Typing.type_of ~refresh:true env) evdref t in let fixprot = try let app = mkApp (delayed_force fix_proto, [|sort; t|]) in Typing.solve_evars env evdref app with e when Errors.noncritical e -> t in (id,None,fixprot) :: env' else (id,None,t) :: env') [] fixnames fixtypes in let env_rec = push_named_context rec_sign env in (* Get interpretation metadatas *) let impls = compute_internalization_env env Recursive fixnames fixtypes fiximps in (* Interp bodies with rollback because temp use of notations/implicit *) let fixdefs = Metasyntax.with_syntax_protection (fun () -> List.iter (Metasyntax.set_notation_for_interpretation impls) notations; List.map4 (fun fixctximpenv -> interp_fix_body env_rec evdref (Id.Map.fold Id.Map.add fixctximpenv impls)) fixctximpenvs fixctxs fixl fixccls) () in (* Instantiate evars and check all are resolved *) let evd = consider_remaining_unif_problems env_rec !evdref in let evd, nf = nf_evars_and_universes evd in let fixdefs = List.map (Option.map nf) fixdefs in let fixtypes = List.map nf fixtypes in let fixctxnames = List.map (fun (_,ctx) -> List.map pi1 ctx) fixctxs in (* Build the fix declaration block *) (env,rec_sign,evd), (fixnames,fixdefs,fixtypes), List.combine3 fixctxnames fiximps fixannots let check_recursive isfix env evd (fixnames,fixdefs,_) = check_evars_are_solved env evd (Evd.empty,evd); if List.for_all Option.has_some fixdefs then begin let fixdefs = List.map Option.get fixdefs in check_mutuality env isfix (List.combine fixnames fixdefs) end let interp_fixpoint l ntns = let (env,_,evd),fix,info = interp_recursive true l ntns in check_recursive true env evd fix; (fix,Evd.evar_universe_context evd,info) let interp_cofixpoint l ntns = let (env,_,evd),fix,info = interp_recursive false l ntns in check_recursive false env evd fix; fix,Evd.evar_universe_context evd,info let declare_fixpoint local poly ((fixnames,fixdefs,fixtypes),ctx,fiximps) indexes ntns = if List.exists Option.is_empty fixdefs then (* Some bodies to define by proof *) let thms = List.map3 (fun id t (len,imps,_) -> (id,(t,(len,imps)))) fixnames fixtypes fiximps in let init_tac = Some (List.map (Option.cata Tacmach.refine_no_check Tacticals.tclIDTAC) fixdefs) in let init_tac = Option.map (List.map Proofview.V82.tactic) init_tac in let evd = Evd.from_ctx ctx in Lemmas.start_proof_with_initialization (Global,poly,DefinitionBody Fixpoint) evd (Some(false,indexes,init_tac)) thms None (Lemmas.mk_hook (fun _ _ -> ())) else begin (* We shortcut the proof process *) let fixdefs = List.map Option.get fixdefs in let fixdecls = prepare_recursive_declaration fixnames fixtypes fixdefs in let env = Global.env() in let indexes = search_guard Loc.ghost env indexes fixdecls in let fiximps = List.map (fun (n,r,p) -> r) fiximps in let vars = Universes.universes_of_constr (mkFix ((indexes,0),fixdecls)) in let fixdecls = List.map_i (fun i _ -> mkFix ((indexes,i),fixdecls)) 0 fixnames in let ctx = Evd.evar_universe_context_set Univ.UContext.empty ctx in let ctx = Universes.restrict_universe_context ctx vars in let fixdecls = List.map Term_typing.mk_pure_proof fixdecls in let ctx = Univ.ContextSet.to_context ctx in ignore (List.map4 (declare_fix (local, poly, Fixpoint) ctx) fixnames fixdecls fixtypes fiximps); (* Declare the recursive definitions *) fixpoint_message (Some indexes) fixnames; end; (* Declare notations *) List.iter Metasyntax.add_notation_interpretation ntns let declare_cofixpoint local poly ((fixnames,fixdefs,fixtypes),ctx,fiximps) ntns = if List.exists Option.is_empty fixdefs then (* Some bodies to define by proof *) let thms = List.map3 (fun id t (len,imps,_) -> (id,(t,(len,imps)))) fixnames fixtypes fiximps in let init_tac = Some (List.map (Option.cata Tacmach.refine_no_check Tacticals.tclIDTAC) fixdefs) in let init_tac = Option.map (List.map Proofview.V82.tactic) init_tac in let evd = Evd.from_ctx ctx in Lemmas.start_proof_with_initialization (Global,poly, DefinitionBody CoFixpoint) evd (Some(true,[],init_tac)) thms None (Lemmas.mk_hook (fun _ _ -> ())) else begin (* We shortcut the proof process *) let fixdefs = List.map Option.get fixdefs in let fixdecls = prepare_recursive_declaration fixnames fixtypes fixdefs in let fixdecls = List.map_i (fun i _ -> mkCoFix (i,fixdecls)) 0 fixnames in let fixdecls = List.map Term_typing.mk_pure_proof fixdecls in let fiximps = List.map (fun (len,imps,idx) -> imps) fiximps in let ctx = Evd.evar_universe_context_set Univ.UContext.empty ctx in let ctx = Univ.ContextSet.to_context ctx in ignore (List.map4 (declare_fix (local, poly, CoFixpoint) ctx) fixnames fixdecls fixtypes fiximps); (* Declare the recursive definitions *) cofixpoint_message fixnames end; (* Declare notations *) List.iter Metasyntax.add_notation_interpretation ntns let extract_decreasing_argument limit = function | (na,CStructRec) -> na | (na,_) when not limit -> na | _ -> error "Only structural decreasing is supported for a non-Program Fixpoint" let extract_fixpoint_components limit l = let fixl, ntnl = List.split l in let fixl = List.map (fun (((_,id),pl),ann,bl,typ,def) -> let ann = extract_decreasing_argument limit ann in {fix_name = id; fix_annot = ann; fix_univs = pl; fix_binders = bl; fix_body = def; fix_type = typ}) fixl in fixl, List.flatten ntnl let extract_cofixpoint_components l = let fixl, ntnl = List.split l in List.map (fun (((_,id),pl),bl,typ,def) -> {fix_name = id; fix_annot = None; fix_univs = pl; fix_binders = bl; fix_body = def; fix_type = typ}) fixl, List.flatten ntnl let out_def = function | Some def -> def | None -> error "Program Fixpoint needs defined bodies." let do_program_recursive local p fixkind fixl ntns = let isfix = fixkind != Obligations.IsCoFixpoint in let (env, rec_sign, evd), fix, info = interp_recursive isfix fixl ntns in (* Program-specific code *) (* Get the interesting evars, those that were not instanciated *) let evd = Typeclasses.resolve_typeclasses ~filter:Typeclasses.no_goals ~fail:true env evd in (* Solve remaining evars *) let evd = nf_evar_map_undefined evd in let collect_evars id def typ imps = (* Generalize by the recursive prototypes *) let def = nf_evar evd (Termops.it_mkNamedLambda_or_LetIn def rec_sign) and typ = nf_evar evd (Termops.it_mkNamedProd_or_LetIn typ rec_sign) in let evars, _, def, typ = Obligations.eterm_obligations env id evd (List.length rec_sign) def typ in (id, def, typ, imps, evars) in let (fixnames,fixdefs,fixtypes) = fix in let fiximps = List.map pi2 info in let fixdefs = List.map out_def fixdefs in let defs = List.map4 collect_evars fixnames fixdefs fixtypes fiximps in let () = if isfix then begin let possible_indexes = List.map compute_possible_guardness_evidences info in let fixdecls = Array.of_list (List.map (fun x -> Name x) fixnames), Array.of_list fixtypes, Array.of_list (List.map (subst_vars (List.rev fixnames)) fixdefs) in let indexes = Pretyping.search_guard Loc.ghost (Global.env ()) possible_indexes fixdecls in List.iteri (fun i _ -> Inductive.check_fix env ((indexes,i),fixdecls)) fixl end in let ctx = Evd.evar_universe_context evd in let kind = match fixkind with | Obligations.IsFixpoint _ -> (local, p, Fixpoint) | Obligations.IsCoFixpoint -> (local, p, CoFixpoint) in Obligations.add_mutual_definitions defs ~kind ctx ntns fixkind let do_program_fixpoint local poly l = let g = List.map (fun ((_,wf,_,_,_),_) -> wf) l in match g, l with | [(n, CWfRec r)], [((((_,id),_),_,bl,typ,def),ntn)] -> let recarg = match n with | Some n -> mkIdentC (snd n) | None -> errorlabstrm "do_program_fixpoint" (str "Recursive argument required for well-founded fixpoints") in build_wellfounded (id, n, bl, typ, out_def def) r recarg ntn | [(n, CMeasureRec (m, r))], [((((_,id),_),_,bl,typ,def),ntn)] -> build_wellfounded (id, n, bl, typ, out_def def) (Option.default (CRef (lt_ref,None)) r) m ntn | _, _ when List.for_all (fun (n, ro) -> ro == CStructRec) g -> let fixl,ntns = extract_fixpoint_components true l in let fixkind = Obligations.IsFixpoint g in do_program_recursive local poly fixkind fixl ntns | _, _ -> errorlabstrm "do_program_fixpoint" (str "Well-founded fixpoints not allowed in mutually recursive blocks") let do_fixpoint local poly l = if Flags.is_program_mode () then do_program_fixpoint local poly l else let fixl, ntns = extract_fixpoint_components true l in let fix = interp_fixpoint fixl ntns in let possible_indexes = List.map compute_possible_guardness_evidences (pi3 fix) in declare_fixpoint local poly fix possible_indexes ntns let do_cofixpoint local poly l = let fixl,ntns = extract_cofixpoint_components l in if Flags.is_program_mode () then do_program_recursive local poly Obligations.IsCoFixpoint fixl ntns else let cofix = interp_cofixpoint fixl ntns in declare_cofixpoint local poly cofix ntns