(* $Id$ *)
-
-(*open Printf
-
-(* PROFILING *)
-(*
-let deref_counter = ref 0
-let apply_subst_context_counter = ref 0
-let apply_subst_metasenv_counter = ref 0
-let lift_counter = ref 0
-let subst_counter = ref 0
-let whd_counter = ref 0
-let are_convertible_counter = ref 0
-let metasenv_length = ref 0
-let context_length = ref 0
-let reset_counters () =
- apply_subst_counter := 0;
- apply_subst_context_counter := 0;
- apply_subst_metasenv_counter := 0;
- lift_counter := 0;
- subst_counter := 0;
- whd_counter := 0;
- are_convertible_counter := 0;
- metasenv_length := 0;
- context_length := 0
-let print_counters () =
- debug_print (lazy (Printf.sprintf
-"apply_subst: %d
-apply_subst_context: %d
-apply_subst_metasenv: %d
-lift: %d
-subst: %d
-whd: %d
-are_convertible: %d
-metasenv length: %d (avg = %.2f)
-context length: %d (avg = %.2f)
-"
- !apply_subst_counter !apply_subst_context_counter
- !apply_subst_metasenv_counter !lift_counter !subst_counter !whd_counter
- !are_convertible_counter !metasenv_length
- ((float !metasenv_length) /. (float !apply_subst_metasenv_counter))
- !context_length
- ((float !context_length) /. (float !apply_subst_context_counter))
- ))*)
-
-
-
exception MetaSubstFailure of string Lazy.t
exception Uncertain of string Lazy.t
-exception AssertFailure of string Lazy.t
-exception DeliftingARelWouldCaptureAFreeVariable;;
-
-let debug_print = fun _ -> ()
-
-type substitution = (int * (Cic.context * Cic.term)) list
-
-(*
-let rec deref subst =
- let third _,_,a = a in
- function
- Cic.Meta(n,l) as t ->
- (try
- deref subst
- (CicSubstitution.subst_meta
- l (third (CicUtil.lookup_subst n subst)))
- with
- CicUtil.Subst_not_found _ -> t)
- | t -> t
-;;
-*)
-
-let lookup_subst = CicUtil.lookup_subst
-;;
-
-(* clean_up_meta take a metasenv and a term and make every local context
-of each occurrence of a metavariable consistent with its canonical context,
-with respect to the hidden hipothesis *)
(*
-let clean_up_meta subst metasenv t =
- let module C = Cic in
- let rec aux t =
- match t with
- C.Rel _
- | C.Sort _ -> t
- | C.Implicit _ -> assert false
- | C.Meta (n,l) as t ->
- let cc =
- (try
- let (cc,_) = lookup_subst n subst in cc
- with CicUtil.Subst_not_found _ ->
- try
- let (_,cc,_) = CicUtil.lookup_meta n metasenv in cc
- with CicUtil.Meta_not_found _ -> assert false) in
- let l' =
- (try
- List.map2
- (fun t1 t2 ->
- match t1,t2 with
- None , _ -> None
- | _ , t -> t) cc l
- with
- Invalid_argument _ -> assert false) in
- C.Meta (n, l')
- | C.Cast (te,ty) -> C.Cast (aux te, aux ty)
- | C.Prod (name,so,dest) -> C.Prod (name, aux so, aux dest)
- | C.Lambda (name,so,dest) -> C.Lambda (name, aux so, aux dest)
- | C.LetIn (name,so,dest) -> C.LetIn (name, aux so, aux dest)
- | C.Appl l -> C.Appl (List.map aux l)
- | C.Var (uri,exp_named_subst) ->
- let exp_named_subst' =
- List.map (fun (uri,t) -> (uri, aux t)) exp_named_subst
- in
- C.Var (uri, exp_named_subst')
- | C.Const (uri, exp_named_subst) ->
- let exp_named_subst' =
- List.map (fun (uri,t) -> (uri, aux t)) exp_named_subst
- in
- C.Const (uri, exp_named_subst')
- | C.MutInd (uri,tyno,exp_named_subst) ->
- let exp_named_subst' =
- List.map (fun (uri,t) -> (uri, aux t)) exp_named_subst
- in
- C.MutInd (uri, tyno, exp_named_subst')
- | C.MutConstruct (uri,tyno,consno,exp_named_subst) ->
- let exp_named_subst' =
- List.map (fun (uri,t) -> (uri, aux t)) exp_named_subst
- in
- C.MutConstruct (uri, tyno, consno, exp_named_subst')
- | C.MutCase (uri,tyno,out,te,pl) ->
- C.MutCase (uri, tyno, aux out, aux te, List.map aux pl)
- | C.Fix (i,fl) ->
- let fl' =
- List.map
- (fun (name,j,ty,bo) -> (name, j, aux ty, aux bo)) fl
- in
- C.Fix (i, fl')
- | C.CoFix (i,fl) ->
- let fl' =
- List.map
- (fun (name,ty,bo) -> (name, aux ty, aux bo)) fl
- in
- C.CoFix (i, fl')
- in
- aux t *)
-
(*** Functions to apply a substitution ***)
let apply_subst_gen ~appl_fun subst term =
(fun (i, _, _) -> not (List.mem_assoc i subst))
metasenv)
-(***** Pretty printing functions ******)
-
-let ppterm ~metasenv subst term =
- CicPp.ppterm ~metasenv (apply_subst subst term)
-
-let ppterm_in_name_context ~metasenv subst term name_context =
- CicPp.pp ~metasenv (apply_subst subst term) name_context
-
-let ppterm_in_context ~metasenv subst term context =
- let name_context =
- List.map (function None -> None | Some (n,_) -> Some n) context
- in
- ppterm_in_name_context ~metasenv subst term name_context
-
-let ppterm_in_context_ref = ref ppterm_in_context
-let set_ppterm_in_context f =
- ppterm_in_context_ref := f
-let use_low_level_ppterm_in_context = ref false
-
-let ppterm_in_context ~metasenv subst term context =
- if !use_low_level_ppterm_in_context then
- ppterm_in_context ~metasenv subst term context
- else
- !ppterm_in_context_ref ~metasenv subst term context
-
-let ppcontext' ~metasenv ?(sep = "\n") subst context =
- let separate s = if s = "" then "" else s ^ sep in
- List.fold_right
- (fun context_entry (i,name_context) ->
- match context_entry with
- Some (n,Cic.Decl t) ->
- sprintf "%s%s : %s" (separate i) (CicPp.ppname n)
- (ppterm_in_name_context ~metasenv subst t name_context),
- (Some n)::name_context
- | Some (n,Cic.Def (bo,ty)) ->
- sprintf "%s%s : %s := %s" (separate i) (CicPp.ppname n)
- (ppterm_in_name_context ~metasenv subst ty name_context)
- (ppterm_in_name_context ~metasenv subst bo name_context), (Some n)::name_context
- | None ->
- sprintf "%s_ :? _" (separate i), None::name_context
- ) context ("",[])
-
-let ppsubst_unfolded ~metasenv subst =
- String.concat "\n"
- (List.map
- (fun (idx, (c, t,ty)) ->
- let context,name_context = ppcontext' ~metasenv ~sep:"; " subst c in
- sprintf "%s |- ?%d : %s := %s" context idx
-(ppterm_in_name_context ~metasenv [] ty name_context)
- (ppterm_in_name_context ~metasenv subst t name_context))
- subst)
-(*
- Printf.sprintf "?%d := %s" idx (CicPp.ppterm term))
- subst) *)
-;;
-
-let ppsubst ~metasenv subst =
- String.concat "\n"
- (List.map
- (fun (idx, (c, t, ty)) ->
- let context,name_context = ppcontext' ~metasenv ~sep:"; " [] c in
- sprintf "%s |- ?%d : %s := %s" context idx (ppterm_in_name_context ~metasenv [] ty name_context)
- (ppterm_in_name_context ~metasenv [] t name_context))
- subst)
-;;
-
-let ppcontext ~metasenv ?sep subst context =
- fst (ppcontext' ~metasenv ?sep subst context)
-
-let ppmetasenv ?(sep = "\n") subst metasenv =
- String.concat sep
- (List.map
- (fun (i, c, t) ->
- let context,name_context = ppcontext' ~metasenv ~sep:"; " subst c in
- sprintf "%s |- ?%d: %s" context i
- (ppterm_in_name_context ~metasenv subst t name_context))
- (List.filter
- (fun (i, _, _) -> not (List.mem_assoc i subst))
- metasenv))
-
let tempi_type_of_aux_subst = ref 0.0;;
let tempi_subst = ref 0.0;;
let tempi_type_of_aux = ref 0.0;;
+*)
-(**** DELIFT ****)
-(* the delift function takes in input a metavariable index, an ordered list of
- * optional terms [t1,...,tn] and a term t, and substitutes every tk = Some
- * (rel(nk)) with rel(k). Typically, the list of optional terms is the explicit
- * substitution that is applied to a metavariable occurrence and the result of
- * the delift function is a term the implicit variable can be substituted with
- * to make the term [t] unifiable with the metavariable occurrence. In general,
- * the problem is undecidable if we consider equivalence in place of alpha
- * convertibility. Our implementation, though, is even weaker than alpha
- * convertibility, since it replace the term [tk] if and only if [tk] is a Rel
- * (missing all the other cases). Does this matter in practice?
- * The metavariable index is the index of the metavariable that must not occur
- * in the term (for occur check).
- *)
+let newmeta =
+ let maxmeta = ref 0 in
+ fun () -> incr maxmeta; !maxmeta
+;;
exception NotInTheList;;
-let position n =
- let rec aux k =
- function
- [] -> raise NotInTheList
- | (Some (Cic.Rel m))::_ when m=n -> k
- | _::tl -> aux (k+1) tl in
- aux 1
+let position n (shift, lc) =
+ match lc with
+ | NCic.Irl len when n <= shift || n > shift + len -> raise NotInTheList
+ | NCic.Irl _ -> n - shift
+ | NCic.Ctx tl ->
+ let rec aux k = function
+ | [] -> raise NotInTheList
+ | (NCic.Rel m)::_ when m + shift = n -> k
+ | _::tl -> aux (k+1) tl
+ in
+ aux 1 tl
+;;
+
+let pack_lc orig =
+ let rec are_contiguous k = function
+ | [] -> true
+ | (NCic.Rel j) :: tl when j = k+1 -> are_contiguous j tl
+ | _ -> false
+ in
+ match orig with
+ | _, NCic.Ctx [] -> 0, NCic.Irl 0
+ | shift, NCic.Ctx (NCic.Rel k::tl as l) when are_contiguous k tl ->
+ shift+k-1, NCic.Irl (List.length l)
+ | _ -> orig
+;;
+
+let mk_restricted_irl shift len restrictions =
+ let rec aux n =
+ if n = 0 then [] else
+ if List.mem (n+shift) restrictions then aux (n-1)
+ else (NCic.Rel n)::aux (n-1)
+ in
+ pack_lc (shift, NCic.Ctx (List.rev (aux len)))
;;
exception Occur;;
-let rec force_does_not_occur subst to_be_restricted t =
- let module C = Cic in
- let more_to_be_restricted = ref [] in
- let rec aux k = function
- C.Rel r when List.mem (r - k) to_be_restricted -> raise Occur
- | C.Rel _
- | C.Sort _ as t -> t
- | C.Implicit _ -> assert false
- | C.Meta (n, l) ->
- (* we do not retrieve the term associated to ?n in subst since *)
- (* in this way we can restrict if something goes wrong *)
- let l' =
- let i = ref 0 in
- List.map
- (function t ->
- incr i ;
- match t with
- None -> None
- | Some t ->
- try
- Some (aux k t)
+let rec force_does_not_occur metasenv subst restrictions t =
+ let rec aux k ms = function
+ | NCic.Rel r when List.mem (r - k) restrictions -> raise Occur
+ | NCic.Meta (n, l) as orig ->
+ (* we ignore the subst since restrict will take care of already
+ * instantiated/restricted metavariabels *)
+ let (metasenv,subst as ms), restrictions_for_n, l' =
+ match l with
+ | shift, NCic.Irl len ->
+ let restrictions =
+ List.filter
+ (fun i -> i > shift && i <= shift + len) restrictions in
+ ms, restrictions, mk_restricted_irl shift len restrictions
+ | shift, NCic.Ctx l ->
+ let ms, _, restrictions_for_n, l =
+ List.fold_right
+ (fun t (ms, i, restrictions_for_n, l) ->
+ try
+ let ms, t = aux (k-shift) ms t in
+ ms, i-1, restrictions_for_n, t::l
with Occur ->
- more_to_be_restricted := (n,!i) :: !more_to_be_restricted;
- None)
- l
- in
- C.Meta (n, l')
- | C.Cast (te,ty) -> C.Cast (aux k te, aux k ty)
- | C.Prod (name,so,dest) -> C.Prod (name, aux k so, aux (k+1) dest)
- | C.Lambda (name,so,dest) -> C.Lambda (name, aux k so, aux (k+1) dest)
- | C.LetIn (name,so,ty,dest) ->
- C.LetIn (name, aux k so, aux k ty, aux (k+1) dest)
- | C.Appl l -> C.Appl (List.map (aux k) l)
- | C.Var (uri,exp_named_subst) ->
- let exp_named_subst' =
- List.map (fun (uri,t) -> (uri, aux k t)) exp_named_subst
- in
- C.Var (uri, exp_named_subst')
- | C.Const (uri, exp_named_subst) ->
- let exp_named_subst' =
- List.map (fun (uri,t) -> (uri, aux k t)) exp_named_subst
- in
- C.Const (uri, exp_named_subst')
- | C.MutInd (uri,tyno,exp_named_subst) ->
- let exp_named_subst' =
- List.map (fun (uri,t) -> (uri, aux k t)) exp_named_subst
- in
- C.MutInd (uri, tyno, exp_named_subst')
- | C.MutConstruct (uri,tyno,consno,exp_named_subst) ->
- let exp_named_subst' =
- List.map (fun (uri,t) -> (uri, aux k t)) exp_named_subst
- in
- C.MutConstruct (uri, tyno, consno, exp_named_subst')
- | C.MutCase (uri,tyno,out,te,pl) ->
- C.MutCase (uri, tyno, aux k out, aux k te, List.map (aux k) pl)
- | C.Fix (i,fl) ->
- let len = List.length fl in
- let k_plus_len = k + len in
- let fl' =
- List.map
- (fun (name,j,ty,bo) -> (name, j, aux k ty, aux k_plus_len bo)) fl
- in
- C.Fix (i, fl')
- | C.CoFix (i,fl) ->
- let len = List.length fl in
- let k_plus_len = k + len in
- let fl' =
- List.map
- (fun (name,ty,bo) -> (name, aux k ty, aux k_plus_len bo)) fl
+ ms, i-1, i::restrictions_for_n, l)
+ l (ms, List.length l, [], [])
+ in
+ ms, restrictions_for_n, pack_lc (shift, NCic.Ctx l)
in
- C.CoFix (i, fl')
- in
- let res = aux 0 t in
- (!more_to_be_restricted, res)
-
-let rec restrict subst to_be_restricted metasenv =
- match to_be_restricted with
- | [] -> metasenv, subst
- | _ ->
- let names_of_context_indexes context indexes =
- String.concat ", "
- (List.map
- (fun i ->
- try
- match List.nth context (i-1) with
- | None -> assert false
- | Some (n, _) -> CicPp.ppname n
- with
- Failure _ -> assert false
- ) indexes)
- in
- let force_does_not_occur_in_context to_be_restricted = function
- | None -> [], None
- | Some (name, Cic.Decl t) ->
- let (more_to_be_restricted, t') =
- force_does_not_occur subst to_be_restricted t
- in
- more_to_be_restricted, Some (name, Cic.Decl t')
- | Some (name, Cic.Def (bo, ty)) ->
- let (more_to_be_restricted, bo') =
- force_does_not_occur subst to_be_restricted bo
- in
- let more_to_be_restricted, ty' =
- let more_to_be_restricted', ty' =
- force_does_not_occur subst to_be_restricted ty
+ if restrictions_for_n = [] then
+ ms, if l = l' then orig else NCic.Meta (n, l')
+ else
+ let metasenv, subst, newmeta =
+ restrict metasenv subst n restrictions_for_n
in
- more_to_be_restricted @ more_to_be_restricted',
- ty'
- in
- more_to_be_restricted, Some (name, Cic.Def (bo', ty'))
- in
- let rec erase i to_be_restricted n = function
- | [] -> [], to_be_restricted, []
- | hd::tl ->
- let more_to_be_restricted,restricted,tl' =
- erase (i+1) to_be_restricted n tl
- in
- let restrict_me = List.mem i restricted in
- if restrict_me then
- more_to_be_restricted, restricted, None:: tl'
- else
- (try
- let more_to_be_restricted', hd' =
- let delifted_restricted =
- let rec aux =
- function
- [] -> []
- | j::tl when j > i -> (j - i)::aux tl
- | _::tl -> aux tl
- in
- aux restricted
- in
- force_does_not_occur_in_context delifted_restricted hd
- in
- more_to_be_restricted @ more_to_be_restricted',
- restricted, hd' :: tl'
- with Occur ->
- more_to_be_restricted, (i :: restricted), None :: tl')
- in
- let (more_to_be_restricted, metasenv) = (* restrict metasenv *)
- List.fold_right
- (fun (n, context, t) (more, metasenv) ->
- let to_be_restricted =
- List.map snd (List.filter (fun (m, _) -> m = n) to_be_restricted)
- in
- let (more_to_be_restricted, restricted, context') =
- (* just an optimization *)
- if to_be_restricted = [] then
- [],[],context
- else
- erase 1 to_be_restricted n context
- in
+ (metasenv, subst), NCic.Meta (newmeta, l')
+ | t -> NCicUntrusted.map_term_fold_a (fun _ k -> k+1) k aux ms t
+ in
+ aux 0 (metasenv,subst) t
+
+and force_does_not_occur_in_context metasenv subst restrictions = function
+ | name, NCic.Decl t as orig ->
+ let (metasenv, subst), t' =
+ force_does_not_occur metasenv subst restrictions t in
+ metasenv, subst, (if t == t' then orig else (name,NCic.Decl t'))
+ | name, NCic.Def (bo, ty) as orig ->
+ let (metasenv, subst), bo' =
+ force_does_not_occur metasenv subst restrictions bo in
+ let (metasenv, subst), ty' =
+ force_does_not_occur metasenv subst restrictions ty in
+ metasenv, subst,
+ (if bo == bo' && ty == ty' then orig else (name, NCic.Def (bo', ty')))
+
+and erase_in_context metasenv subst pos restrictions = function
+ | [] -> metasenv, subst, restrictions, []
+ | hd::tl as orig ->
+ let metasenv, subst, restricted, tl' =
+ erase_in_context metasenv subst (pos+1) restrictions tl in
+ if List.mem pos restricted then
+ metasenv, subst, restricted, tl'
+ else
try
- let more_to_be_restricted', t' =
- force_does_not_occur subst restricted t
+ let metasenv, subst, hd' =
+ let delifted_restricted =
+ List.map ((+) ~-pos) (List.filter ((<=) pos) restricted) in
+ force_does_not_occur_in_context
+ metasenv subst delifted_restricted hd
in
- let metasenv' = (n, context', t') :: metasenv in
- (more @ more_to_be_restricted @ more_to_be_restricted',
- metasenv')
+ metasenv, subst, restricted,
+ (if hd' == hd && tl' == tl then orig else (hd' :: tl'))
with Occur ->
- raise (MetaSubstFailure (lazy (sprintf
- "Cannot restrict the context of the metavariable ?%d over the hypotheses %s since metavariable's type depends on at least one of them"
- n (names_of_context_indexes context to_be_restricted)))))
- metasenv ([], [])
- in
- let (more_to_be_restricted', subst) = (* restrict subst *)
- List.fold_right
- (* TODO: cambiare dopo l'aggiunta del ty *)
- (fun (n, (context, term,ty)) (more, subst') ->
- let to_be_restricted =
- List.map snd (List.filter (fun (m, _) -> m = n) to_be_restricted)
- in
- (try
- let (more_to_be_restricted, restricted, context') =
- (* just an optimization *)
- if to_be_restricted = [] then
- [], [], context
- else
- erase 1 to_be_restricted n context
- in
- let more_to_be_restricted', term' =
- force_does_not_occur subst restricted term
- in
- let more_to_be_restricted'', ty' =
- force_does_not_occur subst restricted ty in
- let subst' = (n, (context', term',ty')) :: subst' in
- let more =
- more @ more_to_be_restricted
- @ more_to_be_restricted'@more_to_be_restricted'' in
- (more, subst')
- with Occur ->
- let error_msg = lazy (sprintf
- "Cannot restrict the context of the metavariable ?%d over the hypotheses %s since ?%d is already instantiated with %s and at least one of the hypotheses occurs in the substituted term"
- n (names_of_context_indexes context to_be_restricted) n
- (ppterm ~metasenv subst term))
- in
- (* DEBUG
- debug_print (lazy error_msg);
- debug_print (lazy ("metasenv = \n" ^ (ppmetasenv metasenv subst)));
- debug_print (lazy ("subst = \n" ^ (ppsubst subst)));
- debug_print (lazy ("context = \n" ^ (ppcontext subst context))); *)
- raise (MetaSubstFailure error_msg)))
- subst ([], [])
- in
- restrict subst (more_to_be_restricted @ more_to_be_restricted') metasenv
+ metasenv, subst, (pos :: restricted), tl'
+
+and restrict metasenv subst i restrictions =
+ assert (restrictions <> []);
+ try
+ let name, ctx, bo, ty = NCicUtils.lookup_subst i subst in
+ try
+ let metasenv, subst, restrictions, newctx =
+ erase_in_context metasenv subst 1 restrictions ctx in
+ let (metasenv, subst), newty =
+ force_does_not_occur metasenv subst restrictions ty in
+ let (metasenv, subst), newbo =
+ force_does_not_occur metasenv subst restrictions bo in
+ let j = newmeta () in
+ let subst_entry_j = j, (name, newctx, newty, newbo) in
+ let reloc_irl = mk_restricted_irl 0 (List.length ctx) restrictions in
+ let subst_entry_i = i, (name, ctx, NCic.Meta (j, reloc_irl), ty) in
+ metasenv,
+ subst_entry_j :: List.map
+ (fun (n,_) as orig -> if i = n then subst_entry_i else orig) subst,
+ j
+ with Occur -> raise (MetaSubstFailure (lazy (Printf.sprintf
+ ("Cannot restrict the context of the metavariable ?%d over "^^
+ "the hypotheses %s since ?%d is already instantiated "^^
+ "with %s and at least one of the hypotheses occurs in "^^
+ "the substituted term") i (String.concat ", "
+ (List.map (fun x -> fst (List.nth ctx (x-1))) restrictions)) i
+ (NCicPp.ppterm ~metasenv ~subst ~context:ctx bo))))
+ with NCicUtils.Subst_not_found _ ->
+ try
+ let name, ctx, ty = NCicUtils.lookup_meta i metasenv in
+ try
+ let metasenv, subst, restrictions, newctx =
+ erase_in_context metasenv subst 1 restrictions ctx in
+ let (metasenv, subst), newty =
+ force_does_not_occur metasenv subst restrictions ty in
+ let j = newmeta () in
+ let metasenv_entry = j, (name, newctx, newty) in
+ let reloc_irl = mk_restricted_irl 0 (List.length ctx) restrictions in
+ let subst_entry = i, (name, ctx, NCic.Meta (j, reloc_irl), ty) in
+ List.map
+ (fun (n,_) as orig -> if i = n then metasenv_entry else orig)
+ metasenv,
+ subst_entry :: subst, j
+ with Occur -> raise (MetaSubstFailure (lazy (Printf.sprintf
+ ("Cannot restrict the context of the metavariable ?%d "^^
+ "over the hypotheses %s since metavariable's type depends "^^
+ "on at least one of them") i (String.concat ", "
+ (List.map (fun x -> fst (List.nth ctx (x-1))) restrictions)))))
+ with
+ | NCicUtils.Meta_not_found _ -> assert false
;;
-(*CSC: maybe we should rename delift in abstract, as I did in my dissertation *)(*Andrea: maybe not*)
-
-let delift n subst context metasenv l t =
(* INVARIANT: we suppose that t is not another occurrence of Meta(n,_),
- otherwise the occur check does not make sense *)
-
-(*
- debug_print (lazy ("sto deliftando il termine " ^ (CicPp.ppterm t) ^ " rispetto
- al contesto locale " ^ (CicPp.ppterm (Cic.Meta(0,l)))));
-*)
-
- let module S = CicSubstitution in
- let l =
- let (_, canonical_context, _) =
- try
- CicUtil.lookup_meta n metasenv
- with CicUtil.Meta_not_found _ ->
- raise (MetaSubstFailure (lazy
- ("delifting error: the metavariable " ^ string_of_int n ^ " is not " ^
- "declared in the metasenv")))
- in
- List.map2 (fun ct lt ->
- match (ct, lt) with
- | None, _ -> None
- | Some _, _ -> lt)
- canonical_context l
- in
- let to_be_restricted = ref [] in
- let rec deliftaux k =
- let module C = Cic in
- function
- | C.Rel m as t->
- if m <=k then
- t
- else
- (try
- match List.nth context (m-k-1) with
- Some (_,C.Def (t,_)) ->
- (try
- C.Rel ((position (m-k) l) + k)
- with
- NotInTheList ->
- (*CSC: Hmmm. This bit of reduction is not in the spirit of *)
- (*CSC: first order unification. Does it help or does it harm? *)
- (*CSC: ANSWER: it hurts performances since it is possible to *)
- (*CSC: have an exponential explosion of the size of the proof.*)
- (*CSC: However, without this bit of reduction some "apply" in *)
- (*CSC: the library fail (e.g. nat/nth_prime.ma). *)
- deliftaux k (S.lift m t))
- | Some (_,C.Decl t) ->
- C.Rel ((position (m-k) l) + k)
- | None -> raise (MetaSubstFailure (lazy "RelToHiddenHypothesis"))
- with
- Failure _ ->
- raise (MetaSubstFailure (lazy "Unbound variable found in deliftaux"))
- )
- | C.Var (uri,exp_named_subst) ->
- let exp_named_subst' =
- List.map (function (uri,t) -> uri,deliftaux k t) exp_named_subst
- in
- C.Var (uri,exp_named_subst')
- | C.Meta (i, l1) as t ->
- (try
- let (_,t,_) = CicUtil.lookup_subst i subst in
- deliftaux k (CicSubstitution.subst_meta l1 t)
- with CicUtil.Subst_not_found _ ->
+ otherwise the occur check does not make sense in case of unification
+ of ?n with ?n *)
+let delift metasenv subst context n l t =
+ let rec aux k (metasenv, subst as ms) = function
+ | NCic.Rel n as t when n <= k -> ms, t
+ | NCic.Rel n ->
+ (try
+ match List.nth context (n-k-1) with
+ | _,NCic.Def (bo,_) ->
+ (try ms, NCic.Rel ((position (n-k) l) + k)
+ with NotInTheList ->
+ (* CSC: This bit of reduction hurts performances since it is
+ * possible to have an exponential explosion of the size of the
+ * proof. required for nat/nth_prime.ma *)
+ aux k ms (NCicSubstitution.lift n bo))
+ | _,NCic.Decl _ -> ms, NCic.Rel ((position (n-k) l) + k)
+ with Failure _ -> assert false) (*Unbound variable found in delift*)
+ | NCic.Meta (i,l1) as orig ->
+ (try
+ let _,_,t,_ = NCicUtils.lookup_subst i subst in
+ aux k ms (NCicSubstitution.subst_meta l1 t)
+ with NCicUtils.Subst_not_found _ ->
(* see the top level invariant *)
if (i = n) then
- raise (MetaSubstFailure (lazy (sprintf
- "Cannot unify the metavariable ?%d with a term that has as subterm %s in which the same metavariable occurs (occur check)"
- i (ppterm ~metasenv subst t))))
- else
- begin
- (* I do not consider the term associated to ?i in subst since *)
- (* in this way I can restrict if something goes wrong. *)
- let rec deliftl j =
- function
- [] -> []
- | None::tl -> None::(deliftl (j+1) tl)
- | (Some t)::tl ->
- let l1' = (deliftl (j+1) tl) in
- try
- Some (deliftaux k t)::l1'
+ raise (MetaSubstFailure (lazy (Printf.sprintf (
+ "Cannot unify the metavariable ?%d with a term that has "^^
+ "as subterm %s in which the same metavariable "^^
+ "occurs (occur check)") i
+ (NCicPp.ppterm ~context ~metasenv ~subst t))))
+ else
+ let shift1,lc1 = l1 in
+ let shift,lc = l in
+ match lc, lc1 with
+ | NCic.Irl len, NCic.Irl len1
+ when shift1 < shift || len1 + shift1 > len + shift ->
+ let restrictions =
+ HExtlib.list_seq 1 (shift - shift1) @
+ HExtlib.list_seq (shift+len+1) (shift1+len1)
+ in
+ let metasenv, subst, newmeta =
+ restrict metasenv subst i restrictions
+ in
+ (metasenv, subst),
+ NCic.Meta(newmeta, mk_restricted_irl shift1 len1 restrictions)
+ | NCic.Irl _, NCic.Irl _ when shift = 0 -> ms, orig
+ | NCic.Irl _, NCic.Irl _ ->
+ ms, NCic.Meta (i, (shift1 - shift, lc1))
+ | _ ->
+ let lc1 = NCicUtils.expand_local_context lc1 in
+ let rec deliftl tbr j ms = function
+ | [] -> ms, tbr, []
+ | t::tl ->
+ let ms, tbr, tl = deliftl tbr (j+1) ms tl in
+ try
+ let ms, t = aux (k-shift1) ms t in
+ ms, tbr, t::tl
with
- NotInTheList
- | MetaSubstFailure _ ->
- to_be_restricted :=
- (i,j)::!to_be_restricted ; None::l1'
- in
- let l' = deliftl 1 l1 in
- C.Meta(i,l')
- end)
- | C.Sort _ as t -> t
- | C.Implicit _ as t -> t
- | C.Cast (te,ty) -> C.Cast (deliftaux k te, deliftaux k ty)
- | C.Prod (n,s,t) -> C.Prod (n, deliftaux k s, deliftaux (k+1) t)
- | C.Lambda (n,s,t) -> C.Lambda (n, deliftaux k s, deliftaux (k+1) t)
- | C.LetIn (n,s,ty,t) ->
- C.LetIn (n, deliftaux k s, deliftaux k ty, deliftaux (k+1) t)
- | C.Appl l -> C.Appl (List.map (deliftaux k) l)
- | C.Const (uri,exp_named_subst) ->
- let exp_named_subst' =
- List.map (function (uri,t) -> uri,deliftaux k t) exp_named_subst
- in
- C.Const (uri,exp_named_subst')
- | C.MutInd (uri,typeno,exp_named_subst) ->
- let exp_named_subst' =
- List.map (function (uri,t) -> uri,deliftaux k t) exp_named_subst
- in
- C.MutInd (uri,typeno,exp_named_subst')
- | C.MutConstruct (uri,typeno,consno,exp_named_subst) ->
- let exp_named_subst' =
- List.map (function (uri,t) -> uri,deliftaux k t) exp_named_subst
- in
- C.MutConstruct (uri,typeno,consno,exp_named_subst')
- | C.MutCase (sp,i,outty,t,pl) ->
- C.MutCase (sp, i, deliftaux k outty, deliftaux k t,
- List.map (deliftaux k) pl)
- | C.Fix (i, fl) ->
- let len = List.length fl in
- let liftedfl =
- List.map
- (fun (name, i, ty, bo) ->
- (name, i, deliftaux k ty, deliftaux (k+len) bo))
- fl
- in
- C.Fix (i, liftedfl)
- | C.CoFix (i, fl) ->
- let len = List.length fl in
- let liftedfl =
- List.map
- (fun (name, ty, bo) -> (name, deliftaux k ty, deliftaux (k+len) bo))
- fl
- in
- C.CoFix (i, liftedfl)
+ | NotInTheList | MetaSubstFailure _ -> ms, j::tbr, tl
+ in
+ let (metasenv, subst), to_be_r, lc1' = deliftl [] 1 ms lc1 in
+ let l1 = pack_lc (shift, NCic.Ctx lc1') in
+ if to_be_r = [] then
+ (metasenv, subst),
+ (if lc1' = lc1 then orig else NCic.Meta (i,l1))
+ else
+ let metasenv, subst, newmeta =
+ restrict metasenv subst i to_be_r in
+ (metasenv, subst), NCic.Meta(newmeta,l1))
+ | t -> NCicUntrusted.map_term_fold_a (fun _ k -> k+1) k aux ms t
in
- let res =
- try
- deliftaux 0 t
- with
- NotInTheList ->
+ try aux 0 (metasenv,subst) t
+ with NotInTheList ->
(* This is the case where we fail even first order unification. *)
(* The reason is that our delift function is weaker than first *)
(* order (in the sense of alpha-conversion). See comment above *)
(* related to the delift function. *)
-(* debug_print (lazy "First Order UnificationFailure during delift") ;
-debug_print(lazy (sprintf
- "Error trying to abstract %s over [%s]: the algorithm only tried to abstract over bound variables"
- (ppterm subst t)
- (String.concat "; "
- (List.map
- (function Some t -> ppterm subst t | None -> "_") l
- )))); *)
- let msg = (lazy (sprintf
- "Error trying to abstract %s over [%s]: the algorithm only tried to abstract over bound variables"
- (ppterm ~metasenv subst t)
- (String.concat "; "
- (List.map
- (function Some t -> ppterm ~metasenv subst t | None -> "_")
- l))))
+ let msg = (lazy (Printf.sprintf
+ ("Error trying to abstract %s over [%s]: the algorithm only tried to "^^
+ "abstract over bound variables") (NCicPp.ppterm ~metasenv ~subst
+ ~context t) (String.concat "; " (List.map (NCicPp.ppterm ~metasenv
+ ~subst ~context) (let shift, lc = l in List.map (NCicSubstitution.lift
+ shift) (NCicUtils.expand_local_context lc))))))
in
+ let shift, lc = l in
+ let lc = NCicUtils.expand_local_context lc in
+ let l = List.map (NCicSubstitution.lift shift) lc in
if
List.exists
- (function
- Some t -> CicUtil.is_meta_closed (apply_subst subst t)
- | None -> true) l
+ (fun t -> NCicUntrusted.metas_of_term subst context t = [])
+ l
then
raise (Uncertain msg)
else
raise (MetaSubstFailure msg)
- in
- let (metasenv, subst) = restrict subst !to_be_restricted metasenv in
- res, metasenv, subst
;;
+(*
(* delifts a term t of n levels strating from k, that is changes (Rel m)
* to (Rel (m - n)) when m > (k + n). if k <= m < k + n delift fails
*)
let delift_rels subst metasenv n t =
delift_rels_from subst metasenv 1 n t
-
-
-(**** END OF DELIFT ****)
+*)
+let mk_meta ?name metasenv context ty =
+ let n = newmeta () in
+ let len = List.length context in
+ let menv_entry = (n, (name, context, ty)) in
+ menv_entry :: metasenv, NCic.Meta (n, (0,NCic.Irl len))
+;;
-(** {2 Format-like pretty printers} *)
-
-let fpp_gen ppf s =
- Format.pp_print_string ppf s;
- Format.pp_print_newline ppf ();
- Format.pp_print_flush ppf ()
-
-let fppsubst ppf subst = fpp_gen ppf (ppsubst ~metasenv:[] subst)
-let fppterm ppf term = fpp_gen ppf (CicPp.ppterm term)
-let fppmetasenv ppf metasenv = fpp_gen ppf (ppmetasenv [] metasenv)
-*)
+let saturate ?(delta=0) metasenv context ty goal_arity =
+ assert (goal_arity >= 0);
+ let rec aux metasenv = function
+ | NCic.Prod (name,s,t) ->
+ let metasenv1, arg = mk_meta ~name:name metasenv context s in
+ let t, metasenv1, args, pno =
+ aux metasenv1 (NCicSubstitution.subst arg t)
+ in
+ if pno + 1 = goal_arity then
+ ty, metasenv, [], goal_arity+1
+ else
+ t, metasenv1, arg::args, pno+1
+ | ty ->
+ match NCicReduction.whd context ty ~delta with
+ | NCic.Prod _ as ty -> aux metasenv ty
+ | ty -> ty, metasenv, [], 0
+ in
+ let res, newmetasenv, arguments, _ = aux metasenv ty in
+ res, newmetasenv, arguments
+;;
projects / helm.git / blobdiff