-(* Copyright (C) 2004, HELM Team.
+(* Copyright (C) 2003, HELM Team.
*
* This file is part of HELM, an Hypertextual, Electronic
* Library of Mathematics, developed at the Computer Science
open Printf
-(* (* PROFILING *)
-let apply_subst_counter = ref 0
+(* 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
metasenv_length := 0;
context_length := 0
let print_counters () =
- prerr_endline (Printf.sprintf
+ debug_print (lazy (Printf.sprintf
"apply_subst: %d
apply_subst_context: %d
apply_subst_metasenv: %d
((float !metasenv_length) /. (float !apply_subst_metasenv_counter))
!context_length
((float !context_length) /. (float !apply_subst_context_counter))
- )
-*)
+ ))*)
+
+
exception MetaSubstFailure of string
exception Uncertain of string
exception AssertFailure of string
-exception SubstNotFound of int
+exception DeliftingARelWouldCaptureAFreeVariable;;
-let debug_print = prerr_endline
+let debug_print = fun _ -> ()
type substitution = (int * (Cic.context * Cic.term)) list
-let lookup_subst n subst =
- try
- List.assoc n subst
- with Not_found -> raise (SubstNotFound n)
+(*
+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 ***)
C.Var (uri, exp_named_subst')
| C.Meta (i, l) ->
(try
- let (context, t) = lookup_subst i subst in
- um_aux (S.lift_meta l t)
- with SubstNotFound _ -> (* unconstrained variable, i.e. free in subst*)
+ let (_, t,_) = lookup_subst i subst in
+ um_aux (S.subst_meta l t)
+ with CicUtil.Subst_not_found _ ->
+ (* unconstrained variable, i.e. free in subst*)
let l' =
List.map (function None -> None | Some t -> Some (um_aux t)) l
in
;;
let apply_subst =
-(* CSC: old code that never performs beta reduction
- let appl_fun um_aux he tl =
- let tl' = List.map um_aux tl in
- begin
- match um_aux he with
- Cic.Appl l -> Cic.Appl (l@tl')
- | he' -> Cic.Appl (he'::tl')
- end
- in
- apply_subst_gen ~appl_fun
-*)
let appl_fun um_aux he tl =
let tl' = List.map um_aux tl in
let t' =
in
begin
match he with
- Cic.Meta (m,_) ->
- let rec beta_reduce =
- function
- (Cic.Appl (Cic.Lambda (_,_,t)::he'::tl')) ->
- let he'' = CicSubstitution.subst he' t in
- if tl' = [] then
- he''
- else
- beta_reduce (Cic.Appl(he''::tl'))
- | t -> t
- in
- beta_reduce t'
+ Cic.Meta (m,_) -> CicReduction.head_beta_reduce t'
| _ -> t'
end
in
(***** Pretty printing functions ******)
-let ppsubst subst =
- String.concat "\n"
- (List.map
- (fun (idx, (_, term)) ->
- Printf.sprintf "?%d := %s" idx (CicPp.ppterm term))
- subst)
-;;
-
let ppterm subst term = CicPp.ppterm (apply_subst subst term)
let ppterm_in_context subst term name_context =
sprintf "%s_ :? _" (separate i), None::name_context
) context ("",[])
+let ppsubst_unfolded subst =
+ String.concat "\n"
+ (List.map
+ (fun (idx, (c, t,_)) ->
+ let context,name_context = ppcontext' ~sep:"; " subst c in
+ sprintf "%s |- ?%d:= %s" context idx
+ (ppterm_in_context subst t name_context))
+ subst)
+(*
+ Printf.sprintf "?%d := %s" idx (CicPp.ppterm term))
+ subst) *)
+;;
+
+let ppsubst subst =
+ String.concat "\n"
+ (List.map
+ (fun (idx, (c, t, _)) ->
+ let context,name_context = ppcontext' ~sep:"; " [] c in
+ sprintf "%s |- ?%d:= %s" context idx
+ (ppterm_in_context [] t name_context))
+ subst)
+;;
+
let ppcontext ?sep subst context = fst (ppcontext' ?sep subst context)
-let ppmetasenv ?(sep = "\n") metasenv subst =
+let ppmetasenv ?(sep = "\n") subst metasenv =
String.concat sep
(List.map
(fun (i, c, t) ->
(fun (i, _, _) -> not (List.mem_assoc i subst))
metasenv))
-(* From now on we recreate a kernel abstraction where substitutions are part of
- * the calculus *)
-
-let lift subst n term =
-(* incr subst_counter; *)
- let term = apply_subst subst term in
- try
- CicSubstitution.lift n term
- with e ->
- raise (MetaSubstFailure ("Lift failure: " ^ Printexc.to_string e))
-
-let subst subst t1 t2 =
-(* incr subst_counter; *)
- let t1 = apply_subst subst t1 in
- let t2 = apply_subst subst t2 in
- try
- CicSubstitution.subst t1 t2
- with e ->
- raise (MetaSubstFailure ("Subst failure: " ^ Printexc.to_string e))
-
-let whd subst context term =
-(* incr whd_counter; *)
- let term = apply_subst subst term in
- let context = apply_subst_context subst context in
- try
- CicReduction.whd context term
- with e ->
- raise (MetaSubstFailure ("Weak head reduction failure: " ^
- Printexc.to_string e))
-
-let are_convertible subst context t1 t2 =
-(* incr are_convertible_counter; *)
- let context = apply_subst_context subst context in
- let t1 = apply_subst subst t1 in
- let t2 = apply_subst subst t2 in
- CicReduction.are_convertible context t1 t2
-
let tempi_type_of_aux_subst = ref 0.0;;
let tempi_subst = ref 0.0;;
let tempi_type_of_aux = ref 0.0;;
- (* assumption: metasenv is already instantiated wrt subst *)
-let type_of_aux' metasenv subst context term =
- let time1 = Unix.gettimeofday () in
- let term = apply_subst subst term in
- let context = apply_subst_context subst context in
-(* let metasenv = apply_subst_metasenv subst metasenv in *)
- let time2 = Unix.gettimeofday () in
- let res =
- try
- CicTypeChecker.type_of_aux' metasenv context term
- with CicTypeChecker.TypeCheckerFailure msg ->
- raise (MetaSubstFailure ("Type checker failure: " ^ msg))
- in
- let time3 = Unix.gettimeofday () in
- tempi_type_of_aux_subst := !tempi_type_of_aux_subst +. time3 -. time1 ;
- tempi_subst := !tempi_subst +. time2 -. time1 ;
- tempi_type_of_aux := !tempi_type_of_aux +. time3 -. time2 ;
- res
-
(**** 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
(List.map
(fun i ->
try
- match List.nth context i with
+ match List.nth context (i-1) with
| None -> assert false
| Some (n, _) -> CicPp.ppname n
with
| [] -> [], to_be_restricted, []
| hd::tl ->
let more_to_be_restricted,restricted,tl' =
- erase (i+1) to_be_restricted n 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'
+ more_to_be_restricted, restricted, None:: tl'
else
(try
let more_to_be_restricted', hd' =
with Occur ->
raise (MetaSubstFailure (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 ([], [])
+ n (names_of_context_indexes context to_be_restricted))))
+ metasenv ([], [])
in
let (more_to_be_restricted', subst) = (* restrict subst *)
List.fold_right
- (fun (n, (context, term)) (more, subst) ->
+ (* 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
let more_to_be_restricted', term' =
force_does_not_occur subst restricted term
in
- let subst' = (n, (context', term')) :: subst in
- let more = more @ more_to_be_restricted @ more_to_be_restricted' 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 ->
- raise (MetaSubstFailure (sprintf
+ let error_msg = 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 subst term)))))
- subst ([], [])
+ (ppterm 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
match more_to_be_restricted @ more_to_be_restricted' with
| [] -> (metasenv, subst)
| l -> restrict subst l metasenv
;;
-(*CSC: maybe we should rename delift in abstract, as I did in my dissertation *)
+(*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, _) = CicUtil.lookup_meta n metasenv in
in
C.Var (uri,exp_named_subst')
| C.Meta (i, l1) as t ->
- if i = n then
- raise (MetaSubstFailure (sprintf
- "Cannot unify the metavariable ?%d with a term that has as subterm %s in which the same metavariable occurs (occur check)"
- i (ppterm subst t)))
- else
- (* 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'
- with
- NotInTheList
- | MetaSubstFailure _ ->
- to_be_restricted := (i,j)::!to_be_restricted ; None::l1'
- in
- let l' = deliftl 1 l1 in
- C.Meta(i,l')
+ (try
+ let (_,t,_) = CicUtil.lookup_subst i subst in
+ deliftaux k (CicSubstitution.subst_meta l1 t)
+ with CicUtil.Subst_not_found _ ->
+ (* see the top level invariant *)
+ if (i = n) then
+ raise (MetaSubstFailure (sprintf
+ "Cannot unify the metavariable ?%d with a term that has as subterm %s in which the same metavariable occurs (occur check)"
+ i (ppterm 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'
+ 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)
(* 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 "\n!!!!!!!!!!! First Order UnificationFailure, but maybe it could have been successful even in a first order setting (no conversion, only alpha convertibility)! Please, implement a better 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
+ )))); *)
raise (Uncertain (sprintf
"Error trying to abstract %s over [%s]: the algorithm only tried to abstract over bound variables"
(ppterm subst t)
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_from subst metasenv k n =
+ let rec liftaux subst metasenv k =
+ let module C = Cic in
+ function
+ C.Rel m ->
+ if m < k then
+ C.Rel m, subst, metasenv
+ else if m < k + n then
+ raise DeliftingARelWouldCaptureAFreeVariable
+ else
+ C.Rel (m - n), subst, metasenv
+ | C.Var (uri,exp_named_subst) ->
+ let exp_named_subst',subst,metasenv =
+ List.fold_right
+ (fun (uri,t) (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
+ in
+ C.Var (uri,exp_named_subst'),subst,metasenv
+ | C.Meta (i,l) ->
+ (try
+ let (_, t,_) = lookup_subst i subst in
+ liftaux subst metasenv k (CicSubstitution.subst_meta l t)
+ with CicUtil.Subst_not_found _ ->
+ let l',to_be_restricted,subst,metasenv =
+ let rec aux con l subst metasenv =
+ match l with
+ [] -> [],[],subst,metasenv
+ | he::tl ->
+ let tl',to_be_restricted,subst,metasenv =
+ aux (con + 1) tl subst metasenv in
+ let he',more_to_be_restricted,subst,metasenv =
+ match he with
+ None -> None,[],subst,metasenv
+ | Some t ->
+ try
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ Some t',[],subst,metasenv
+ with
+ DeliftingARelWouldCaptureAFreeVariable ->
+ None,[i,con],subst,metasenv
+ in
+ he'::tl',more_to_be_restricted@to_be_restricted,subst,metasenv
+ in
+ aux 1 l subst metasenv in
+ let metasenv,subst = restrict subst to_be_restricted metasenv in
+ C.Meta(i,l'),subst,metasenv)
+ | C.Sort _ as t -> t,subst,metasenv
+ | C.Implicit _ as t -> t,subst,metasenv
+ | C.Cast (te,ty) ->
+ let te',subst,metasenv = liftaux subst metasenv k te in
+ let ty',subst,metasenv = liftaux subst metasenv k ty in
+ C.Cast (te',ty'),subst,metasenv
+ | C.Prod (n,s,t) ->
+ let s',subst,metasenv = liftaux subst metasenv k s in
+ let t',subst,metasenv = liftaux subst metasenv (k+1) t in
+ C.Prod (n,s',t'),subst,metasenv
+ | C.Lambda (n,s,t) ->
+ let s',subst,metasenv = liftaux subst metasenv k s in
+ let t',subst,metasenv = liftaux subst metasenv (k+1) t in
+ C.Lambda (n,s',t'),subst,metasenv
+ | C.LetIn (n,s,t) ->
+ let s',subst,metasenv = liftaux subst metasenv k s in
+ let t',subst,metasenv = liftaux subst metasenv (k+1) t in
+ C.LetIn (n,s',t'),subst,metasenv
+ | C.Appl l ->
+ let l',subst,metasenv =
+ List.fold_right
+ (fun t (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ t'::l,subst,metasenv) l ([],subst,metasenv) in
+ C.Appl l',subst,metasenv
+ | C.Const (uri,exp_named_subst) ->
+ let exp_named_subst',subst,metasenv =
+ List.fold_right
+ (fun (uri,t) (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
+ in
+ C.Const (uri,exp_named_subst'),subst,metasenv
+ | C.MutInd (uri,tyno,exp_named_subst) ->
+ let exp_named_subst',subst,metasenv =
+ List.fold_right
+ (fun (uri,t) (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
+ in
+ C.MutInd (uri,tyno,exp_named_subst'),subst,metasenv
+ | C.MutConstruct (uri,tyno,consno,exp_named_subst) ->
+ let exp_named_subst',subst,metasenv =
+ List.fold_right
+ (fun (uri,t) (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
+ in
+ C.MutConstruct (uri,tyno,consno,exp_named_subst'),subst,metasenv
+ | C.MutCase (sp,i,outty,t,pl) ->
+ let outty',subst,metasenv = liftaux subst metasenv k outty in
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ let pl',subst,metasenv =
+ List.fold_right
+ (fun t (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ t'::l,subst,metasenv) pl ([],subst,metasenv)
+ in
+ C.MutCase (sp,i,outty',t',pl'),subst,metasenv
+ | C.Fix (i, fl) ->
+ let len = List.length fl in
+ let liftedfl,subst,metasenv =
+ List.fold_right
+ (fun (name, i, ty, bo) (l,subst,metasenv) ->
+ let ty',subst,metasenv = liftaux subst metasenv k ty in
+ let bo',subst,metasenv = liftaux subst metasenv (k+len) bo in
+ (name,i,ty',bo')::l,subst,metasenv
+ ) fl ([],subst,metasenv)
+ in
+ C.Fix (i, liftedfl),subst,metasenv
+ | C.CoFix (i, fl) ->
+ let len = List.length fl in
+ let liftedfl,subst,metasenv =
+ List.fold_right
+ (fun (name, ty, bo) (l,subst,metasenv) ->
+ let ty',subst,metasenv = liftaux subst metasenv k ty in
+ let bo',subst,metasenv = liftaux subst metasenv (k+len) bo in
+ (name,ty',bo')::l,subst,metasenv
+ ) fl ([],subst,metasenv)
+ in
+ C.CoFix (i, liftedfl),subst,metasenv
+ in
+ liftaux subst metasenv k
+
+let delift_rels subst metasenv n t =
+ delift_rels_from subst metasenv 1 n t
+
+
(**** END OF DELIFT ****)
let fppsubst ppf subst = fpp_gen ppf (ppsubst subst)
let fppterm ppf term = fpp_gen ppf (CicPp.ppterm term)
-let fppmetasenv ppf metasenv = fpp_gen ppf (ppmetasenv metasenv [])
+let fppmetasenv ppf metasenv = fpp_gen ppf (ppmetasenv [] metasenv)