type binder_type =
- Declaration
- | Definition
+ Declaration of Cic.name * Cic.term
+ | Definition of Cic.name * Cic.term
;;
-type context = (binder_type * Cic.name * Cic.term) list;;
+type metasenv = (int * Cic.term) list;;
-type sequent = context * Cic.term;;
+type named_context = binder_type list;;
+
+type sequent = named_context * Cic.term;;
+
+let proof =
+ ref (None : (UriManager.uri * metasenv * Cic.term * Cic.term) option)
+;;
+(*CSC: Quando facciamo Clear di una ipotesi, cosa succede? *)
+(* Note: the sequent is redundant: it can be computed from the type of the *)
+(* metavariable and its context in the proof. We keep it just for efficiency *)
+(* because computing the context of a term may be quite expensive. *)
+let goal = ref (None : (int * sequent) option);;
+
+exception NotImplemented
+
+let cic_context_of_named_context =
+ List.map
+ (function
+ Declaration (_,t) -> Cic.Decl t
+ | Definition (_,t) -> Cic.Def t
+ )
+;;
+
+let refine_meta meta term newmetasenv =
+ let (uri,metasenv,bo,ty) =
+ match !proof with
+ None -> assert false
+ | Some (uri,metasenv,bo,ty) -> uri,metasenv,bo,ty
+ in
+ let metasenv' = newmetasenv @ (List.remove_assoc meta metasenv) in
+ let rec aux =
+ let module C = Cic in
+ function
+ C.Rel _ as t -> t
+ | C.Var _ as t -> t
+ | C.Meta meta' when meta=meta' -> term
+ | C.Meta _ as t -> t
+ | C.Sort _ as t -> t
+ | C.Implicit as t -> t
+ | C.Cast (te,ty) -> C.Cast (aux te, aux ty)
+ | C.Prod (n,s,t) -> C.Prod (n, aux s, aux t)
+ | C.Lambda (n,s,t) -> C.Lambda (n, aux s, aux t)
+ | C.LetIn (n,s,t) -> C.LetIn (n, aux s, aux t)
+ | C.Appl l -> C.Appl (List.map aux l)
+ | C.Const _ as t -> t
+ | C.Abst _ as t -> t
+ | C.MutInd _ as t -> t
+ | C.MutConstruct _ as t -> t
+ | C.MutCase (sp,cookingsno,i,outt,t,pl) ->
+ C.MutCase (sp,cookingsno,i,aux outt, aux t,
+ List.map aux pl)
+ | C.Fix (i,fl) ->
+ let substitutedfl =
+ List.map
+ (fun (name,i,ty,bo) -> (name, i, aux ty, aux bo))
+ fl
+ in
+ C.Fix (i, substitutedfl)
+ | C.CoFix (i,fl) ->
+ let substitutedfl =
+ List.map
+ (fun (name,ty,bo) -> (name, aux ty, aux bo))
+ fl
+ in
+ C.CoFix (i, substitutedfl)
+ in
+ let metasenv'' = List.map (function i,ty -> i,(aux ty)) metasenv' in
+ let bo' = aux bo in
+ proof := Some (uri,metasenv'',bo',ty)
+;;
+
+(* Returns the first meta whose number is above the number of the higher meta. *)
+let new_meta () =
+ let metasenv =
+ match !proof with
+ None -> assert false
+ | Some (_,metasenv,_,_) -> metasenv
+ in
+ let rec aux =
+ function
+ None,[] -> 1
+ | Some n,[] -> n
+ | None,(n,_)::tl -> aux (Some n,tl)
+ | Some m,(n,_)::tl -> if n > m then aux (Some n,tl) else aux (Some m,tl)
+ in
+ 1 + aux (None,metasenv)
+;;
+
+(* metas_in_term term *)
+(* Returns the ordered list of the metas that occur in [term]. *)
+(* Duplicates are removed. The implementation is not very efficient. *)
+let metas_in_term term =
+ let module C = Cic in
+ let rec aux =
+ function
+ C.Rel _
+ | C.Var _ -> []
+ | C.Meta n -> [n]
+ | C.Sort _
+ | C.Implicit -> []
+ | C.Cast (te,ty) -> (aux te) @ (aux ty)
+ | C.Prod (_,s,t) -> (aux s) @ (aux t)
+ | C.Lambda (_,s,t) -> (aux s) @ (aux t)
+ | C.LetIn (_,s,t) -> (aux s) @ (aux t)
+ | C.Appl l -> List.fold_left (fun i t -> i @ (aux t)) [] l
+ | C.Const _
+ | C.Abst _
+ | C.MutInd _
+ | C.MutConstruct _ -> []
+ | C.MutCase (sp,cookingsno,i,outt,t,pl) ->
+ (aux outt) @ (aux t) @
+ (List.fold_left (fun i t -> i @ (aux t)) [] pl)
+ | C.Fix (i,fl) ->
+ List.fold_left (fun i (_,_,ty,bo) -> i @ (aux bo) @ (aux ty)) [] fl
+ | C.CoFix (i,fl) ->
+ List.fold_left (fun i (_,ty,bo) -> i @ (aux bo) @ (aux ty)) [] fl
+ in
+ let metas = aux term in
+ let rec elim_duplicates =
+ function
+ [] -> []
+ | he::tl ->
+ he::(elim_duplicates (List.filter (function el -> he <> el) tl))
+ in
+ elim_duplicates metas
+;;
+
+(* perforate context term ty *)
+(* replaces the term [term] in the proof with a new metavariable whose type *)
+(* is [ty]. [context] must be the context of [term] in the whole proof. This *)
+(* could be easily computed; so the only reasons to have it as an argument *)
+(* are efficiency reasons. *)
+let perforate context term ty =
+ let module C = Cic in
+ let newmeta = new_meta () in
+ match !proof with
+ None -> assert false
+ | Some (uri,metasenv,bo,gty) ->
+ (* We push the new meta at the end of the list for pretty-printing *)
+ (* purposes: in this way metas are ordered. *)
+ let metasenv' = metasenv@[newmeta,ty] in
+ let bo' = ProofEngineReduction.replace term (C.Meta newmeta) bo in
+ (* It may be possible that some metavariables occurred only in *)
+ (* the term we are perforating and they now occurs no more. We *)
+ (* get rid of them, collecting the really useful metavariables *)
+ (* in metasenv''. *)
+ let newmetas = metas_in_term bo' in
+ let metasenv'' =
+ List.filter (function (n,_) -> List.mem n newmetas) metasenv'
+ in
+ proof := Some (uri,metasenv'',bo',gty) ;
+ goal := Some (newmeta,(context,ty)) ;
+ newmeta
+;;
+
+(************************************************************)
+(* Some easy tactics. *)
+(************************************************************)
+
+exception Fail of string;;
+
+let intros () =
+ let module C = Cic in
+ let module R = CicReduction in
+ let metasenv =
+ match !proof with
+ None -> assert false
+ | Some (_,metasenv,_,_) -> metasenv
+ in
+ let (metano,context,ty) =
+ match !goal with
+ None -> assert false
+ | Some (metano,(context,ty)) -> metano,context,ty
+ in
+ let newmeta = new_meta () in
+ let rec collect_context =
+ function
+ C.Cast (te,_) -> collect_context te
+ | C.Prod (n,s,t) ->
+ let (ctx,ty,bo) = collect_context t in
+ let n' =
+ match n with
+ C.Name _ -> n
+(*CSC: generatore di nomi? Chiedere il nome? *)
+ | C.Anonimous -> C.Name "fresh_name"
+ in
+ ((Declaration (n',s))::ctx,ty,C.Lambda(n',s,bo))
+ | C.LetIn (n,s,t) ->
+ let (ctx,ty,bo) = collect_context t in
+ ((Definition (n,s))::ctx,ty,C.LetIn(n,s,bo))
+ | _ as t -> [], t, (C.Meta newmeta)
+ in
+ let revcontext',ty',bo' = collect_context ty in
+ let context'' = (List.rev revcontext') @ context in
+ refine_meta metano bo' [newmeta,ty'] ;
+ goal := Some (newmeta,(context'',ty'))
+;;
+
+(* The term bo must be closed in the current context *)
+let exact bo =
+ let module T = CicTypeChecker in
+ let module R = CicReduction in
+ let metasenv =
+ match !proof with
+ None -> assert false
+ | Some (_,metasenv,_,_) -> metasenv
+ in
+ let (metano,context,ty) =
+ match !goal with
+ None -> assert false
+ | Some (metano,(context,ty)) ->
+ assert (ty = List.assoc metano metasenv) ;
+ (* Invariant: context is the actual context of the meta in the proof *)
+ metano,context,ty
+ in
+ let context = cic_context_of_named_context context in
+ if R.are_convertible (T.type_of_aux' metasenv context bo) ty then
+ begin
+ refine_meta metano bo [] ;
+ goal := None
+ end
+ else
+ raise (Fail "The type of the provided term is not the one expected.")
+;;
+
+let fix_andreas_meta mgu mgut =
+ let mgul = Array.to_list mgu in
+ let mgutl = Array.to_list mgut in
+ let applymetas_to_metas =
+ let newmeta = new_meta () in
+ (* WARNING: here we are using the invariant that above the most *)
+ (* recente new_meta() there are no used metas. *)
+ Array.init (List.length mgul) (function i -> newmeta + i) in
+ (* WARNING!!!!!!!!!!!!!!!!!!!!!!!!!!!!! *)
+ (* Here we assume that either a META has been instantiated with *)
+ (* a close term or with itself. *)
+ let uninstantiatedmetas =
+ List.fold_right2
+ (fun bo ty newmetas ->
+ let module C = Cic in
+ match bo with
+ Cic.Meta i ->
+ let newmeta = applymetas_to_metas.(i) in
+ (*CSC: se ty contiene metas, queste hanno il numero errato!!! *)
+ let ty_with_newmetas =
+ (* Substitues (META n) with (META (applymetas_to_metas.(n))) *)
+ let rec aux =
+ function
+ C.Rel _
+ | C.Var _ as t -> t
+ | C.Meta n -> C.Meta (applymetas_to_metas.(n))
+ | C.Sort _
+ | C.Implicit as t -> t
+ | C.Cast (te,ty) -> C.Cast (aux te, aux ty)
+ | C.Prod (n,s,t) -> C.Prod (n, aux s, aux t)
+ | C.Lambda (n,s,t) -> C.Lambda (n, aux s, aux t)
+ | C.LetIn (n,s,t) -> C.LetIn (n, aux s, aux t)
+ | C.Appl l -> C.Appl (List.map aux l)
+ | C.Const _ as t -> t
+ | C.Abst _ -> assert false
+ | C.MutInd _
+ | C.MutConstruct _ as t -> t
+ | C.MutCase (sp,cookingsno,i,outt,t,pl) ->
+ C.MutCase (sp,cookingsno,i,aux outt, aux t,
+ List.map aux pl)
+ | C.Fix (i,fl) ->
+ let substitutedfl =
+ List.map
+ (fun (name,i,ty,bo) -> (name, i, aux ty, aux bo))
+ fl
+ in
+ C.Fix (i, substitutedfl)
+ | C.CoFix (i,fl) ->
+ let substitutedfl =
+ List.map
+ (fun (name,ty,bo) -> (name, aux ty, aux bo))
+ fl
+ in
+ C.CoFix (i, substitutedfl)
+ in
+ aux ty
+ in
+ (newmeta,ty_with_newmetas)::newmetas
+ | _ -> newmetas
+ ) mgul mgutl []
+ in
+ let mgul' =
+ List.map
+ (function
+ Cic.Meta i -> Cic.Meta (applymetas_to_metas.(i))
+ | _ as t -> t
+ ) mgul
+ in
+ mgul',uninstantiatedmetas
+;;
+
+(* The term bo must be closed in the current context *)
+let apply term =
+ let module T = CicTypeChecker in
+ let module R = CicReduction in
+ let module C = Cic in
+ let metasenv =
+ match !proof with
+ None -> assert false
+ | Some (_,metasenv,_,_) -> metasenv
+ in
+ let (metano,context,ty) =
+ match !goal with
+ None -> assert false
+ | Some (metano,(context,ty)) ->
+ assert (ty = List.assoc metano metasenv) ;
+ (* Invariant: context is the actual context of the meta in the proof *)
+ metano,context,ty
+ in
+ let ciccontext = cic_context_of_named_context context in
+ let mgu,mgut = CicUnification.apply metasenv ciccontext term ty in
+ let mgul',uninstantiatedmetas = fix_andreas_meta mgu mgut in
+ let bo' =
+ if List.length mgul' = 0 then
+ term
+ else
+ Cic.Appl (term::mgul')
+ in
+ refine_meta metano bo' uninstantiatedmetas ;
+ match uninstantiatedmetas with
+ (n,ty)::tl -> goal := Some (n,(context,ty))
+ | [] -> goal := None
+;;
+
+
+let eta_expand metasenv ciccontext t arg =
+ let module T = CicTypeChecker in
+ let module S = CicSubstitution in
+ let module C = Cic in
+ let rec aux n =
+ function
+ t' when t' = S.lift n arg -> C.Rel (1 + n)
+ | C.Rel m -> if m <= n then C.Rel m else C.Rel (m+1)
+ | C.Var _
+ | C.Meta _
+ | C.Sort _
+ | C.Implicit as t -> t
+ | C.Cast (te,ty) -> C.Cast (aux n te, aux n ty)
+ | C.Prod (nn,s,t) -> C.Prod (nn, aux n s, aux (n+1) t)
+ | C.Lambda (nn,s,t) -> C.Lambda (nn, aux n s, aux (n+1) t)
+ | C.LetIn (nn,s,t) -> C.LetIn (nn, aux n s, aux (n+1) t)
+ | C.Appl l -> C.Appl (List.map (aux n) l)
+ | C.Const _ as t -> t
+ | C.Abst _ -> assert false
+ | C.MutInd _
+ | C.MutConstruct _ as t -> t
+ | C.MutCase (sp,cookingsno,i,outt,t,pl) ->
+ C.MutCase (sp,cookingsno,i,aux n outt, aux n t,
+ List.map (aux n) pl)
+ | C.Fix (i,fl) ->
+ let tylen = List.length fl in
+ let substitutedfl =
+ List.map
+ (fun (name,i,ty,bo) -> (name, i, aux n ty, aux (n+tylen) bo))
+ fl
+ in
+ C.Fix (i, substitutedfl)
+ | C.CoFix (i,fl) ->
+ let tylen = List.length fl in
+ let substitutedfl =
+ List.map
+ (fun (name,ty,bo) -> (name, aux n ty, aux (n+tylen) bo))
+ fl
+ in
+ C.CoFix (i, substitutedfl)
+ in
+ let argty =
+ T.type_of_aux' metasenv ciccontext arg
+ in
+ (C.Appl [C.Lambda ((C.Name "dummy"),argty,aux 0 t) ; arg])
+;;
+
+exception NotAnInductiveTypeToEliminate;;
+exception NotTheRightEliminatorShape;;
+exception NoHypothesesFound;;
+
+let elim term =
+ let module T = CicTypeChecker in
+ let module U = UriManager in
+ let module R = CicReduction in
+ let module C = Cic in
+ let curi,metasenv =
+ match !proof with
+ None -> assert false
+ | Some (curi,metasenv,_,_) -> curi,metasenv
+ in
+ let (metano,context,ty) =
+ match !goal with
+ None -> assert false
+ | Some (metano,(context,ty)) ->
+ assert (ty = List.assoc metano metasenv) ;
+ (* Invariant: context is the actual context of the meta in the proof *)
+ metano,context,ty
+ in
+ let ciccontext = cic_context_of_named_context context in
+ let termty = T.type_of_aux' metasenv ciccontext term in
+ let uri,cookingno,typeno,args =
+ match termty with
+ C.MutInd (uri,cookingno,typeno) -> (uri,cookingno,typeno,[])
+ | C.Appl ((C.MutInd (uri,cookingno,typeno))::args) ->
+ (uri,cookingno,typeno,args)
+ | _ -> raise NotAnInductiveTypeToEliminate
+ in
+ let eliminator_uri =
+ let buri = U.buri_of_uri uri in
+ let name =
+ match CicEnvironment.get_cooked_obj uri cookingno with
+ C.InductiveDefinition (tys,_,_) ->
+ let (name,_,_,_) = List.nth tys typeno in
+ name
+ | _ -> assert false
+ in
+ let ext =
+ match T.type_of_aux' metasenv ciccontext ty with
+ C.Sort C.Prop -> "_ind"
+ | C.Sort C.Set -> "_rec"
+ | C.Sort C.Type -> "_rect"
+ | _ -> assert false
+ in
+ U.uri_of_string (buri ^ "/" ^ name ^ ext ^ ".con")
+ in
+ let eliminator_cookingno =
+ UriManager.relative_depth curi eliminator_uri 0
+ in
+ let eliminator_ref = C.Const (eliminator_uri,eliminator_cookingno) in
+ let ety =
+ T.type_of_aux' [] [] eliminator_ref
+ in
+
+ let earity = CicUnification.get_arity ety in
+ let mgu = Array.init earity (fun i -> (C.Meta i)) in
+ let mgut = Array.make earity C.Implicit in
+ (* Here we assume that we have only one inductive hypothesis to *)
+ (* eliminate and that it is the last hypothesis of the theorem. *)
+ (* A better approach would be fingering the hypotheses in some *)
+ (* way. *)
+ let hypothesis_to_eliminate,econclusion =
+ (* aux n h t *)
+ (* traverses the backbone [t] looking for the last hypothesis *)
+ (* and substituting Pi-abstractions with META declarations. *)
+ (* [h] is the last hypothesis met up to now. [n] is the next *)
+ (* unused META. *)
+ let rec aux n h =
+ function
+ C.Prod (_,s,t) ->
+ mgut.(n) <- s ;
+ aux (n+1) (Some s) (CicSubstitution.subst (C.Meta n) t)
+ | C.Cast (te,_) -> aux n h te
+ | t -> match h with
+ None -> raise NoHypothesesFound
+ | Some h' -> h',t
+ in
+ aux 0 None ety
+ in
+prerr_endline ("HTOELIM: " ^ CicPp.ppterm hypothesis_to_eliminate) ;
+prerr_endline ("ECONCLUSION: " ^ CicPp.ppterm econclusion) ;
+flush stderr ;
+ ignore (CicUnification.fo_unif_mgu 0 hypothesis_to_eliminate termty mgu) ;
+ ignore (CicUnification.fo_unif_mgu 0 term (C.Meta (earity - 1)) mgu) ;
+ let mgu = CicUnification.unwind mgu in
+prerr_endline "Dopo l'unwind dell'mgu"; flush stderr ;
+ let mark = Array.make earity 1 in
+ let ueconclusion =
+ CicUnification.unwind_meta mgu mark econclusion
+ in
+prerr_endline ("ECONCLUSION DOPO UNWIND: " ^ CicPp.ppterm ueconclusion) ;
+flush stderr ;
+ (* The conclusion of our elimination principle is *)
+ (* (?i farg1 ... fargn) *)
+ (* The conclusion of our goal is ty. So, we can *)
+ (* eta-expand ty w.r.t. farg1 .... fargn to get *)
+ (* a new ty equal to (P farg1 ... fargn). Now *)
+ (* ?i can be instantiated with P and we are ready *)
+ (* to refine the term. *)
+ let emeta, fargs =
+ match ueconclusion with
+ C.Appl ((C.Meta emeta)::fargs) -> emeta,fargs
+ | _ -> raise NotTheRightEliminatorShape
+ in
+ let eta_expanded_ty =
+(*CSC: metasenv e ?????????????*)
+ List.fold_left (eta_expand metasenv ciccontext) ty fargs
+ in
+(*CSC: 0????????*)
+prerr_endline ("ETAEXPANDEDTY:" ^ CicPp.ppterm eta_expanded_ty) ; flush stdout ;
+ ignore (CicUnification.fo_unif_mgu 0 ueconclusion eta_expanded_ty mgu) ;
+prerr_endline "Dopo la seconda unificazione" ; flush stdout ;
+ let mgu = CicUnification.unwind mgu in
+ print_endline "unwind"; flush stdout;
+ (* When unwinding the META that corresponds to the elimination *)
+ (* predicate (which is emeta), we must also perform one-step *)
+ (* beta-reduction. *)
+ let mgut =
+ let mark = Array.make (Array.length mgu) 1 in
+ Array.map
+ (CicUnification.unwind_meta_reducing mgu mark (Some emeta))
+ mgut ;
+ in
+ print_endline "unwind_array"; flush stdout;
+ let mgu' = Array.copy mgu in
+ let mgut' = CicUnification.list_of_array mgut in
+ print_endline "list"; flush stdout;
+ Array.iteri
+ (fun i ty ->
+prerr_endline ("META " ^ string_of_int i ^ ": " ^ CicPp.ppterm mgu'.(i) ^
+ " == " ^ CicPp.ppterm ty) ; flush stderr ;
+ let ty' =
+ CicTypeChecker.type_of_aux' mgut' ciccontext mgu'.(i)
+ in
+ ignore (CicUnification.fo_unif_mgu 0 ty ty' mgu)
+ ) mgut ;
+ let mgu = CicUnification.unwind mgu in
+ let mgut = CicUnification.unwind_array mgu mgut in
+prerr_endline "Dopo le unwind dell'mgut" ; flush stdout ;
+ let mgul',uninstantiatedmetas = fix_andreas_meta mgu mgut in
+prerr_endline "Dopo il fissaggio" ; flush stdout ;
+ let bo' = Cic.Appl (eliminator_ref::mgul') in
+prerr_endline ("BODY': " ^ CicPp.ppterm bo') ; flush stdout ;
+ refine_meta metano bo' uninstantiatedmetas ;
+prerr_endline "dopo refine meta" ; flush stdout ;
+ match uninstantiatedmetas with
+ (n,ty)::tl -> goal := Some (n,(context,ty))
+ | [] -> goal := None
+;;
+
+let elim_intros term =
+ elim term ;
+ intros ()
+;;
+
+let reduction_tactic reduction_function term =
+ let curi,metasenv,pbo,pty =
+ match !proof with
+ None -> assert false
+ | Some (curi,metasenv,bo,ty) -> curi,metasenv,bo,ty
+ in
+ let (metano,context,ty) =
+ match !goal with
+ None -> assert false
+ | Some (metano,(context,ty)) -> metano,context,ty
+ in
+ let term' = reduction_function term in
+ (* We don't know if [term] is a subterm of [ty] or a subterm of *)
+ (* the type of one metavariable. So we replace it everywhere. *)
+ (*CSC: ma si potrebbe ovviare al problema. Ma non credo *)
+ (*CSC: che si guadagni nulla in fatto di efficienza. *)
+ let replace = ProofEngineReduction.replace ~what:term ~with_what:term' in
+ let ty' = replace ty in
+ let context' =
+ List.map
+ (function
+ Definition (n,t) -> Definition (n,replace t)
+ | Declaration (n,t) -> Declaration (n,replace t)
+ ) context
+ in
+ let metasenv' =
+ List.map
+ (function
+ (n,_) when n = metano -> (metano,ty')
+ | _ as t -> t
+ ) metasenv
+ in
+ proof := Some (curi,metasenv',pbo,pty) ;
+ goal := Some (metano,(context',ty'))
+;;
+
+let reduction_tactic_in_scratch reduction_function ty term =
+ let metasenv =
+ match !proof with
+ None -> []
+ | Some (_,metasenv,_,_) -> metasenv
+ in
+ let context =
+ match !goal with
+ None -> []
+ | Some (_,(context,_)) -> context
+ in
+ let term' = reduction_function term in
+ ProofEngineReduction.replace ~what:term ~with_what:term' ~where:ty
+;;
+
+let whd = reduction_tactic CicReduction.whd;;
+let reduce = reduction_tactic ProofEngineReduction.reduce;;
+let simpl = reduction_tactic ProofEngineReduction.simpl;;
+
+let whd_in_scratch = reduction_tactic_in_scratch CicReduction.whd;;
+let reduce_in_scratch =
+ reduction_tactic_in_scratch ProofEngineReduction.reduce;;
+let simpl_in_scratch =
+ reduction_tactic_in_scratch ProofEngineReduction.simpl;;
+
+(* It is just the opposite of whd. The code should probably be merged. *)
+let fold term =
+ let curi,metasenv,pbo,pty =
+ match !proof with
+ None -> assert false
+ | Some (curi,metasenv,bo,ty) -> curi,metasenv,bo,ty
+ in
+ let (metano,context,ty) =
+ match !goal with
+ None -> assert false
+ | Some (metano,(context,ty)) -> metano,context,ty
+ in
+ let term' = CicReduction.whd term in
+ (* We don't know if [term] is a subterm of [ty] or a subterm of *)
+ (* the type of one metavariable. So we replace it everywhere. *)
+ (*CSC: ma si potrebbe ovviare al problema. Ma non credo *)
+ (*CSC: che si guadagni nulla in fatto di efficienza. *)
+ let replace = ProofEngineReduction.replace ~what:term' ~with_what:term in
+ let ty' = replace ty in
+ let context' =
+ List.map
+ (function
+ Declaration (n,t) -> Declaration (n,replace t)
+ | Definition (n,t) -> Definition (n,replace t)
+ ) context
+ in
+ let metasenv' =
+ List.map
+ (function
+ (n,_) when n = metano -> (metano,ty')
+ | _ as t -> t
+ ) metasenv
+ in
+ proof := Some (curi,metasenv',pbo,pty) ;
+ goal := Some (metano,(context',ty'))
+;;
+
+let cut term =
+ let module C = Cic in
+ let curi,metasenv,pbo,pty =
+ match !proof with
+ None -> assert false
+ | Some (curi,metasenv,bo,ty) -> curi,metasenv,bo,ty
+ in
+ let (metano,context,ty) =
+ match !goal with
+ None -> assert false
+ | Some (metano,(context,ty)) -> metano,context,ty
+ in
+ let newmeta1 = new_meta () in
+ let newmeta2 = newmeta1 + 1 in
+ let newmeta1ty = CicSubstitution.lift 1 ty in
+ let bo' =
+ C.Appl
+ [C.Lambda (C.Name "dummy_for_cut",term,C.Meta newmeta1) ;
+ C.Meta newmeta2]
+ in
+prerr_endline ("BO': " ^ CicPp.ppterm bo') ; flush stderr ;
+ refine_meta metano bo' [newmeta2,term; newmeta1,newmeta1ty];
+ goal :=
+ Some
+ (newmeta1,((Declaration (C.Name "dummy_for_cut", term))::context,
+ newmeta1ty))
+;;
+
+let letin term =
+ let module C = Cic in
+ let curi,metasenv,pbo,pty =
+ match !proof with
+ None -> assert false
+ | Some (curi,metasenv,bo,ty) -> curi,metasenv,bo,ty
+ in
+ let (metano,context,ty) =
+ match !goal with
+ None -> assert false
+ | Some (metano,(context,ty)) -> metano,context,ty
+ in
+ let ciccontext = cic_context_of_named_context context in
+ let _ = CicTypeChecker.type_of_aux' metasenv ciccontext term in
+ let newmeta = new_meta () in
+ let newmetaty = CicSubstitution.lift 1 ty in
+ let bo' = C.LetIn (C.Name "dummy_for_letin",term,C.Meta newmeta) in
+ refine_meta metano bo' [newmeta,newmetaty];
+ goal :=
+ Some
+ (newmeta,
+ ((Definition (C.Name "dummy_for_letin", term))::context, newmetaty))
+;;
+
+exception NotConvertible;;
+
+(*CSC: Bug (or feature?). [input] is parsed in the context of the goal, *)
+(*CSC: while [goal_input] can have a richer context (because of binders) *)
+(*CSC: So it is _NOT_ possible to use those binders in the [input] term. *)
+(*CSC: Is that evident? Is that right? Or should it be changed? *)
+let change ~goal_input ~input =
+ let curi,metasenv,pbo,pty =
+ match !proof with
+ None -> assert false
+ | Some (curi,metasenv,bo,ty) -> curi,metasenv,bo,ty
+ in
+ let (metano,context,ty) =
+ match !goal with
+ None -> assert false
+ | Some (metano,(context,ty)) -> metano,context,ty
+ in
+ let ciccontext = cic_context_of_named_context context in
+ (* are_convertible works only on well-typed terms *)
+ ignore (CicTypeChecker.type_of_aux' metasenv ciccontext input) ;
+ if CicReduction.are_convertible goal_input input then
+ begin
+ let ty' = ProofEngineReduction.replace goal_input input ty in
+ let metasenv' =
+ List.map
+ (function
+ (n,_) when n = metano -> (metano,ty')
+ | _ as t -> t
+ ) metasenv
+ in
+ proof := Some (curi,metasenv',pbo,pty) ;
+ goal := Some (metano,(context,ty'))
+ end
+ else
+ raise NotConvertible
+;;