X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Fcic_proof_checking%2FcicElim.ml;h=c668d1c9be33420a1b9222a8646c8c3408b7a436;hb=4167cea65ca58897d1a3dbb81ff95de5074700cc;hp=fb64aae09f00c3ff5437de495f03b69bde458d24;hpb=d27e9241c554dc82f1e7703d0d3ebec3a66776a7;p=helm.git diff --git a/helm/ocaml/cic_proof_checking/cicElim.ml b/helm/ocaml/cic_proof_checking/cicElim.ml index fb64aae09..c668d1c9b 100644 --- a/helm/ocaml/cic_proof_checking/cicElim.ml +++ b/helm/ocaml/cic_proof_checking/cicElim.ml @@ -25,31 +25,32 @@ open Printf -exception Elim_failure of string +exception Elim_failure of string Lazy.t exception Can_t_eliminate -let fresh_binder = - let counter = ref ~-1 in - function - | true -> - incr counter; - Cic.Name ("e" ^ string_of_int !counter) - | _ -> Cic.Anonymous +let debug_print = fun _ -> () +(*let debug_print s = prerr_endline (Lazy.force s) *) + +let counter = ref ~-1 ;; + +let fresh_binder () = Cic.Name "matita_dummy" +(* + incr counter; + Cic.Name ("e" ^ string_of_int !counter) *) (** verifies if a given inductive type occurs in a term in target position *) -let rec recursive uri typeno subst = function - | Cic.Prod (_, _, target) -> recursive uri typeno subst target - | Cic.MutInd (uri', typeno', subst') - | Cic.Appl (Cic.MutInd (uri', typeno', subst') :: _) -> - UriManager.eq uri uri' && typeno = typeno' && subst = subst' -(* | Cic.Appl args -> List.exists (recursive uri typeno subst) args *) +let rec recursive uri typeno = function + | Cic.Prod (_, _, target) -> recursive uri typeno target + | Cic.MutInd (uri', typeno', []) + | Cic.Appl (Cic.MutInd (uri', typeno', []) :: _) -> + UriManager.eq uri uri' && typeno = typeno' | _ -> false (** given a list of constructor types, return true if at least one of them is * recursive, false otherwise *) -let recursive_type uri typeno subst constructors = +let recursive_type uri typeno constructors = let rec aux = function - | Cic.Prod (_, src, tgt) -> recursive uri typeno subst src || aux tgt + | Cic.Prod (_, src, tgt) -> recursive uri typeno src || aux tgt | _ -> false in List.exists (fun (_, ty) -> aux ty) constructors @@ -68,11 +69,10 @@ let rec split l n = * @param paramsno number of Prod to ignore in this constructor (i.e. number of * inductive parameters) * @param dependent true if we are in the dependent case (i.e. sort <> Prop) *) -let rec delta (uri, typeno, subst) dependent paramsno consno t p args = - assert (subst = []); +let rec delta (uri, typeno) dependent paramsno consno t p args = match t with - | Cic.MutInd (uri', typeno', subst') when - UriManager.eq uri uri' && typeno = typeno' && subst = subst' -> + | Cic.MutInd (uri', typeno', []) when + UriManager.eq uri uri' && typeno = typeno' -> if dependent then (match args with | [] -> assert false @@ -80,8 +80,8 @@ let rec delta (uri, typeno, subst) dependent paramsno consno t p args = | _ -> unfold_appl (Cic.Appl [p; unfold_appl (Cic.Appl args)])) else p - | Cic.Appl (Cic.MutInd (uri', typeno', subst') :: tl) when - UriManager.eq uri uri' && typeno = typeno' && subst = subst' -> + | Cic.Appl (Cic.MutInd (uri', typeno', []) :: tl) when + UriManager.eq uri uri' && typeno = typeno' -> let (lparams, rparams) = split tl paramsno in if dependent then (match args with @@ -95,22 +95,22 @@ let rec delta (uri, typeno, subst) dependent paramsno consno t p args = | [] -> p | _ -> Cic.Appl (p :: rparams)) | Cic.Prod (binder, src, tgt) -> - if recursive uri typeno subst src then + if recursive uri typeno src then let args = List.map (CicSubstitution.lift 2) args in let phi = let src = CicSubstitution.lift 1 src in - delta (uri, typeno, subst) dependent paramsno consno src + delta (uri, typeno) dependent paramsno consno src (CicSubstitution.lift 1 p) [Cic.Rel 1] in let tgt = CicSubstitution.lift 1 tgt in - Cic.Prod (fresh_binder dependent, src, + Cic.Prod (fresh_binder (), src, Cic.Prod (Cic.Anonymous, phi, - delta (uri, typeno, subst) dependent paramsno consno tgt + delta (uri, typeno) dependent paramsno consno tgt (CicSubstitution.lift 2 p) (args @ [Cic.Rel 2]))) else (* non recursive *) let args = List.map (CicSubstitution.lift 1) args in - Cic.Prod (fresh_binder dependent, src, - delta (uri, typeno, subst) dependent paramsno consno tgt + Cic.Prod (fresh_binder (), src, + delta (uri, typeno) dependent paramsno consno tgt (CicSubstitution.lift 1 p) (args @ [Cic.Rel 1])) | _ -> assert false @@ -126,9 +126,9 @@ let rec strip_left_params consno leftno = function strip_left_params consno (leftno - 1) tgt | _ -> assert false -let delta (ury, typeno, subst) dependent paramsno consno t p args = +let delta (ury, typeno) dependent paramsno consno t p args = let t = strip_left_params consno paramsno t in - delta (ury, typeno, subst) dependent paramsno consno t p args + delta (ury, typeno) dependent paramsno consno t p args let rec add_params binder indno ty eliminator = if indno = 0 then @@ -136,6 +136,11 @@ let rec add_params binder indno ty eliminator = else match ty with | Cic.Prod (name, src, tgt) -> + let name = + match name with + Cic.Name _ -> name + | Cic.Anonymous -> fresh_binder () + in binder name src (add_params binder (indno - 1) tgt eliminator) | _ -> assert false @@ -153,7 +158,15 @@ let rec count_pi = function let rec type_of_p sort dependent leftno indty = function | Cic.Prod (n, src, tgt) when leftno = 0 -> - Cic.Prod (n, src, type_of_p sort dependent leftno indty tgt) + let n = + if dependent then + match n with + Cic.Name _ -> n + | Cic.Anonymous -> fresh_binder () + else + n + in + Cic.Prod (n, src, type_of_p sort dependent leftno indty tgt) | Cic.Prod (_, _, tgt) -> type_of_p sort dependent (leftno - 1) indty tgt | t -> if dependent then @@ -163,14 +176,14 @@ let rec type_of_p sort dependent leftno indty = function let rec add_right_pi dependent strip liftno liftfrom rightno indty = function | Cic.Prod (_, src, tgt) when strip = 0 -> - Cic.Prod (fresh_binder true, - CicSubstitution.lift_from (liftfrom + 1) liftno src, + Cic.Prod (fresh_binder (), + CicSubstitution.lift_from liftfrom liftno src, add_right_pi dependent strip liftno (liftfrom + 1) rightno indty tgt) | Cic.Prod (_, _, tgt) -> add_right_pi dependent (strip - 1) liftno liftfrom rightno indty tgt | t -> if dependent then - Cic.Prod (fresh_binder dependent, + Cic.Prod (fresh_binder (), CicSubstitution.lift_from (rightno + 1) liftno indty, Cic.Appl (Cic.Rel (1 + liftno + rightno) :: mk_rels 0 (rightno + 1))) else @@ -184,70 +197,69 @@ let rec add_right_pi dependent strip liftno liftfrom rightno indty = function let rec add_right_lambda dependent strip liftno liftfrom rightno indty case = function | Cic.Prod (_, src, tgt) when strip = 0 -> - Cic.Lambda (fresh_binder true, - CicSubstitution.lift_from (liftfrom + 1) liftno src, + Cic.Lambda (fresh_binder (), + CicSubstitution.lift_from liftfrom liftno src, add_right_lambda dependent strip liftno (liftfrom + 1) rightno indty case tgt) | Cic.Prod (_, _, tgt) -> - add_right_lambda dependent (strip - 1) liftno liftfrom rightno indty + add_right_lambda true (strip - 1) liftno liftfrom rightno indty case tgt | t -> - Cic.Lambda (fresh_binder true, + Cic.Lambda (fresh_binder (), CicSubstitution.lift_from (rightno + 1) liftno indty, case) -let string_of_sort = function - | Cic.Prop -> "Prop" - | Cic.CProp -> "CProp" - | Cic.Set -> "Set" - | Cic.Type _ -> "Type" - -let rec branch (uri, typeno, subst) insource paramsno t fix head args = - assert (subst = []); +let rec branch (uri, typeno) insource paramsno t fix head args = match t with - | Cic.MutInd (uri', typeno', subst') when - UriManager.eq uri uri' && typeno = typeno' && subst = subst' -> - let head = if insource then fix else head in - (match args with - | [] -> head - | _ -> Cic.Appl (head :: args)) - | Cic.Appl (Cic.MutInd (uri', typeno', subst') :: tl) when - UriManager.eq uri uri' && typeno = typeno' && subst = subst' -> + | Cic.MutInd (uri', typeno', []) when + UriManager.eq uri uri' && typeno = typeno' -> + if insource then + (match args with + | [arg] -> Cic.Appl (fix :: args) + | _ -> Cic.Appl (head :: [Cic.Appl args])) + else + (match args with + | [] -> head + | _ -> Cic.Appl (head :: args)) + | Cic.Appl (Cic.MutInd (uri', typeno', []) :: tl) when + UriManager.eq uri uri' && typeno = typeno' -> if insource then let (lparams, rparams) = split tl paramsno in - Cic.Appl (fix :: rparams @ args) + match args with + | [arg] -> Cic.Appl (fix :: rparams @ args) + | _ -> Cic.Appl (fix :: rparams @ [Cic.Appl args]) else (match args with | [] -> head | _ -> Cic.Appl (head :: args)) | Cic.Prod (binder, src, tgt) -> - if recursive uri typeno subst src then + if recursive uri typeno src then let args = List.map (CicSubstitution.lift 1) args in let phi = let fix = CicSubstitution.lift 1 fix in let src = CicSubstitution.lift 1 src in - branch (uri, typeno, subst) true paramsno src fix head [Cic.Rel 1] + branch (uri, typeno) true paramsno src fix head [Cic.Rel 1] in - Cic.Lambda (fresh_binder true, src, - branch (uri, typeno, subst) insource paramsno tgt + Cic.Lambda (fresh_binder (), src, + branch (uri, typeno) insource paramsno tgt (CicSubstitution.lift 1 fix) (CicSubstitution.lift 1 head) (args @ [Cic.Rel 1; phi])) else (* non recursive *) let args = List.map (CicSubstitution.lift 1) args in - Cic.Lambda (fresh_binder true, src, - branch (uri, typeno, subst) insource paramsno tgt + Cic.Lambda (fresh_binder (), src, + branch (uri, typeno) insource paramsno tgt (CicSubstitution.lift 1 fix) (CicSubstitution.lift 1 head) (args @ [Cic.Rel 1])) | _ -> assert false -let branch (uri, typeno, subst) insource liftno paramsno t fix head args = +let branch (uri, typeno) insource liftno paramsno t fix head args = let t = strip_left_params liftno paramsno t in - branch (uri, typeno, subst) insource paramsno t fix head args + branch (uri, typeno) insource paramsno t fix head args -let elim_of ?(sort = Cic.Type (CicUniv.fresh ())) uri typeno = - let (obj, univ) = (CicEnvironment.get_obj uri CicUniv.empty_ugraph) in - let subst = [] in +let elim_of ~sort uri typeno = + counter := ~-1; + let (obj, univ) = (CicEnvironment.get_obj CicUniv.empty_ugraph uri) in match obj with - | Cic.InductiveDefinition (indTypes, params, leftno) -> + | Cic.InductiveDefinition (indTypes, params, leftno, _) -> let (name, inductive, ty, constructors) = try List.nth indTypes typeno @@ -256,19 +268,23 @@ let elim_of ?(sort = Cic.Type (CicUniv.fresh ())) uri typeno = let paramsno = count_pi ty in (* number of (left or right) parameters *) let rightno = paramsno - leftno in let dependent = (strip_pi ty <> Cic.Sort Cic.Prop) in +let head = match strip_pi ty with Cic.Sort s -> s in let conslen = List.length constructors in let consno = ref (conslen + 1) in - if (not dependent) && (sort <> Cic.Prop) && (conslen > 1) then - raise Can_t_eliminate; + if + not + (CicTypeChecker.check_allowed_sort_elimination uri typeno head sort) + then + raise Can_t_eliminate; let indty = - let indty = Cic.MutInd (uri, typeno, subst) in + let indty = Cic.MutInd (uri, typeno, []) in if paramsno = 0 then indty else Cic.Appl (indty :: mk_rels 0 paramsno) in let mk_constructor consno = - let constructor = Cic.MutConstruct (uri, typeno, consno, subst) in + let constructor = Cic.MutConstruct (uri, typeno, consno, []) in if leftno = 0 then constructor else @@ -286,7 +302,7 @@ let elim_of ?(sort = Cic.Type (CicUniv.fresh ())) uri typeno = decr consno; let p = Cic.Rel !consno in Cic.Prod (Cic.Anonymous, - (delta (uri, typeno, subst) dependent leftno !consno + (delta (uri, typeno) dependent leftno !consno constructor p [mk_constructor !consno]), acc)) constructors final_ty)) @@ -296,27 +312,41 @@ let elim_of ?(sort = Cic.Type (CicUniv.fresh ())) uri typeno = let consno = ref (conslen + 1) in let eliminator_body = let fix = Cic.Rel (rightno + 2) in - let is_recursive = recursive_type uri typeno subst constructors in + let is_recursive = recursive_type uri typeno constructors in let recshift = if is_recursive then 1 else 0 in let (_, branches) = List.fold_right (fun (_, ty) (shift, branches) -> let head = Cic.Rel (rightno + shift + 1 + recshift) in let b = - branch (uri, typeno, subst) false + branch (uri, typeno) false (rightno + conslen + 2 + recshift) leftno ty fix head [] in (shift + 1, b :: branches)) constructors (1, []) in + let shiftno = conslen + rightno + 2 + recshift in + let outtype = + if dependent then + Cic.Rel shiftno + else + let head = + if rightno = 0 then + CicSubstitution.lift 1 (Cic.Rel shiftno) + else + Cic.Appl + ((CicSubstitution.lift (rightno + 1) (Cic.Rel shiftno)) :: + mk_rels 1 rightno) + in + add_right_lambda true leftno shiftno 1 rightno indty head ty + in let mutcase = - Cic.MutCase (uri, typeno, Cic.Rel (conslen + rightno + 2 + recshift), - Cic.Rel 1, branches) + Cic.MutCase (uri, typeno, outtype, Cic.Rel 1, branches) in let body = if is_recursive then let fixfun = - add_right_lambda dependent leftno (conslen + 2) 2 rightno + add_right_lambda dependent leftno (conslen + 2) 1 rightno indty mutcase ty in (* rightno is the decreasing argument, i.e. the argument of @@ -332,8 +362,8 @@ let elim_of ?(sort = Cic.Type (CicUniv.fresh ())) uri typeno = (fun (_, constructor) acc -> decr consno; let p = Cic.Rel !consno in - Cic.Lambda (fresh_binder true, - (delta (uri, typeno, subst) dependent leftno !consno + Cic.Lambda (fresh_binder (), + (delta (uri, typeno) dependent leftno !consno constructor p [mk_constructor !consno]), acc)) constructors body)) @@ -341,16 +371,24 @@ let elim_of ?(sort = Cic.Type (CicUniv.fresh ())) uri typeno = add_params (fun b s t -> Cic.Lambda (b, s, t)) leftno ty cic in (* -prerr_endline (CicPp.ppterm eliminator_type); -prerr_endline (CicPp.ppterm eliminator_body); +debug_print (lazy (CicPp.ppterm eliminator_type)); +debug_print (lazy (CicPp.ppterm eliminator_body)); +*) + let eliminator_type = + FreshNamesGenerator.mk_fresh_names [] [] [] eliminator_type in + let eliminator_body = + FreshNamesGenerator.mk_fresh_names [] [] [] eliminator_body in +(* +debug_print (lazy (CicPp.ppterm eliminator_type)); +debug_print (lazy (CicPp.ppterm eliminator_body)); *) let (computed_type, ugraph) = try CicTypeChecker.type_of_aux' [] [] eliminator_body CicUniv.empty_ugraph with CicTypeChecker.TypeCheckerFailure msg -> - raise (Elim_failure (sprintf + raise (Elim_failure (lazy (sprintf "type checker failure while type checking:\n%s\nerror:\n%s" - (CicPp.ppterm eliminator_body) msg)) + (CicPp.ppterm eliminator_body) (Lazy.force msg)))) in if not (fst (CicReduction.are_convertible [] eliminator_type computed_type ugraph)) @@ -366,6 +404,12 @@ prerr_endline (CicPp.ppterm eliminator_body); | _ -> assert false in let name = UriManager.name_of_uri uri ^ suffix in - Cic.Constant (name, Some eliminator_body, eliminator_type, []) - | _ -> assert false + let buri = UriManager.buri_of_uri uri in + let uri = UriManager.uri_of_string (buri ^ "/" ^ name ^ ".con") in + let obj_attrs = [`Class (`Elim sort); `Generated] in + uri, + Cic.Constant (name, Some eliminator_body, eliminator_type, [], obj_attrs) + | _ -> + failwith (sprintf "not an inductive definition (%s)" + (UriManager.string_of_uri uri))