X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Fng_kernel%2FnCicReduction.ml;h=236f5778e86394317930eababfede4aaedc8fb3e;hb=f9abd21eb0d26cf9b632af4df819225be4d091e3;hp=1815ceedfcf5c87e9d387068ffbfb039c76763ff;hpb=0542386e10041791982e7240f281299677b1997b;p=helm.git diff --git a/helm/software/components/ng_kernel/nCicReduction.ml b/helm/software/components/ng_kernel/nCicReduction.ml index 1815ceedf..236f5778e 100644 --- a/helm/software/components/ng_kernel/nCicReduction.ml +++ b/helm/software/components/ng_kernel/nCicReduction.ml @@ -17,46 +17,64 @@ module E = NCicEnvironment exception AssertFailure of string Lazy.t;; +let debug = ref false;; +let pp m = if !debug then prerr_endline (Lazy.force m) else ();; + module type Strategy = sig type stack_term type env_term type config = int * env_term list * C.term * stack_term list val to_env : - reduce: (config -> config * bool) -> unwind: (config -> C.term) -> + reduce: (delta:int -> config -> config * bool) -> + unwind: (config -> C.term) -> config -> env_term - val from_stack : stack_term -> config + val from_stack : delta:int -> stack_term -> config val from_stack_list_for_unwind : - unwind: (config -> C.term) -> stack_term list -> C.term list - val from_env : env_term -> config + unwind: (config -> C.term) -> stack_term list -> C.term list + val from_env : delta:int -> env_term -> config val from_env_for_unwind : - unwind: (config -> C.term) -> env_term -> C.term + unwind: (config -> C.term) -> env_term -> C.term val stack_to_env : - reduce: (config -> config * bool) -> unwind: (config -> C.term) -> + reduce: (delta:int -> config -> config * bool) -> + unwind: (config -> C.term) -> stack_term -> env_term val compute_to_env : - reduce: (config -> config * bool) -> unwind: (config -> C.term) -> + reduce: (delta:int -> config -> config * bool) -> + unwind: (config -> C.term) -> int -> env_term list -> C.term -> env_term val compute_to_stack : - reduce: (config -> config * bool) -> unwind: (config -> C.term) -> + reduce: (delta:int -> config -> config * bool) -> + unwind: (config -> C.term) -> config -> stack_term end ;; -module CallByValueByNameForUnwind' = struct +module CallByValueByNameForUnwind' : Strategy = struct type config = int * env_term list * C.term * stack_term list - and stack_term = config lazy_t * C.term lazy_t (* cbv, cbn *) - and env_term = config lazy_t * C.term lazy_t (* cbv, cbn *) - let to_env ~reduce ~unwind c = lazy (fst (reduce c)),lazy (unwind c) - let from_stack (c,_) = Lazy.force c + and stack_term = + config Lazy.t * (int -> config) * C.term Lazy.t + and env_term = + config Lazy.t (* cbneed ~delta:0 *) + * (int -> config) (* cbvalue ~delta *) + * C.term Lazy.t (* cbname ~delta:max_int *) + let to_env ~reduce ~unwind c = + lazy (fst (reduce ~delta:0 c)), + (fun delta -> fst (reduce ~delta c)), + lazy (unwind c) + let from_stack ~delta (c0,c,_) = if delta = 0 then Lazy.force c0 else c delta let from_stack_list_for_unwind ~unwind:_ l = - List.map (function (_,c) -> Lazy.force c) l - let from_env (c,_) = Lazy.force c - let from_env_for_unwind ~unwind:_ (_,c) = Lazy.force c + List.map (fun (_,_,c) -> Lazy.force c) l + let from_env ~delta (c0,c,_) = if delta = 0 then Lazy.force c0 else c delta + let from_env_for_unwind ~unwind:_ (_,_,c) = Lazy.force c let stack_to_env ~reduce:_ ~unwind:_ config = config let compute_to_env ~reduce ~unwind k e t = - lazy (fst (reduce (k,e,t,[]))), lazy (unwind (k,e,t,[])) + lazy (fst (reduce ~delta:0 (k,e,t,[]))), + (fun delta -> fst (reduce ~delta (k,e,t,[]))), + lazy (unwind (k,e,t,[])) let compute_to_stack ~reduce ~unwind config = - lazy (fst (reduce config)), lazy (unwind config) + lazy (fst (reduce ~delta:0 config)), + (fun delta -> fst (reduce ~delta config)), + lazy (unwind config) end ;; @@ -87,7 +105,7 @@ module Reduction(RS : Strategy) = struct let rec reduce ~delta ?(subst = []) context : config -> config * bool = let rec aux = function | k, e, C.Rel n, s when n <= k -> - let k',e',t',s' = RS.from_env (list_nth e (n-1)) in + let k',e',t',s' = RS.from_env ~delta (list_nth e (n-1)) in aux (k',e',t',s'@s) | k, _, C.Rel n, s as config (* when n > k *) -> let x= try Some (List.nth context (n - 1 - k)) with Failure _ -> None in @@ -104,14 +122,15 @@ module Reduction(RS : Strategy) = struct | (_, _, C.Prod _, _) | (_, _, C.Lambda _, []) as config -> config, true | (k, e, C.Lambda (_,_,t), p::s) -> - aux (k+1, (RS.stack_to_env ~reduce:aux ~unwind p)::e, t,s) + aux (k+1, (RS.stack_to_env ~reduce:(reduce ~subst context) ~unwind p)::e, t,s) | (k, e, C.LetIn (_,_,m,t), s) -> - let m' = RS.compute_to_env ~reduce:aux ~unwind k e m in + let m' = RS.compute_to_env ~reduce:(reduce ~subst context) ~unwind k e m in aux (k+1, m'::e, t, s) | (_, _, C.Appl ([]|[_]), _) -> assert false | (k, e, C.Appl (he::tl), s) -> let tl' = - List.map (fun t->RS.compute_to_stack ~reduce:aux ~unwind (k,e,t,[])) tl + List.map (fun t->RS.compute_to_stack + ~reduce:(reduce ~subst context) ~unwind (k,e,t,[])) tl in aux (k, e, he, tl' @ s) | (_, _, C.Const @@ -125,29 +144,32 @@ module Reduction(RS : Strategy) = struct (Ref.Decl|Ref.Ind _|Ref.Con _|Ref.CoFix _))), _) as config -> config, true | (_, _, (C.Const (Ref.Ref - (_,Ref.Fix (fixno,recindex,height)) as refer) as head),s) as config -> -(* if delta >= height then config else *) - (match - try Some (RS.from_stack (List.nth s recindex)) - with Failure _ -> None - with - | None -> config, true - | Some recparam -> - let fixes,_,_ = NCicEnvironment.get_checked_fixes_or_cofixes refer in - match reduce ~delta:0 ~subst context recparam with - | (_,_,C.Const (Ref.Ref (_,Ref.Con _)), _) as c, _ - when delta >= height -> - let new_s = - replace recindex s (RS.compute_to_stack ~reduce:aux ~unwind c) - in - (0, [], head, new_s), false - | (_,_,C.Const (Ref.Ref (_,Ref.Con _)), _) as c, _ -> - let new_s = - replace recindex s (RS.compute_to_stack ~reduce:aux ~unwind c) - in - let _,_,_,_,body = List.nth fixes fixno in - aux (0, [], body, new_s) - | _ -> config, true) + (_,Ref.Fix (fixno,recindex,height)) as refer)),s) as config -> + (let arg = try Some (List.nth s recindex) with Failure _ -> None in + match arg with + None -> config, true + | Some arg -> + let fixes,(_,_,pragma),_ = + NCicEnvironment.get_checked_fixes_or_cofixes refer in + if delta >= height then + match pragma with + | `Projection -> + (match RS.from_stack ~delta:max_int arg with + | _,_,C.Const(Ref.Ref(_,Ref.Con _)),_::_ -> + let _,_,_,_,body = List.nth fixes fixno in + aux (0, [], body, s) + | _ -> config,false) + | _ -> config,false + else + match RS.from_stack ~delta:0 arg with + | (_,_,C.Const (Ref.Ref (_,Ref.Con _)), _) as c -> + let new_s = + replace recindex s + (RS.compute_to_stack ~reduce:(reduce ~subst context) + ~unwind c) in + let _,_,_,_,body = List.nth fixes fixno in + aux (0, [], body, new_s) + | _ -> config, true) | (k, e, C.Match (_,_,term,pl),s) as config -> let decofix = function | (_,_,C.Const(Ref.Ref(_,Ref.CoFix c)as refer),s)-> @@ -190,127 +212,132 @@ let get_relevance = ref (fun ~metasenv:_ ~subst:_ _ _ -> assert false);; let set_get_relevance f = get_relevance := f;; +let alpha_eq ~test_lambda_source aux test_eq_only metasenv subst context t1 t2 = + if t1 === t2 then + true + else + match (t1,t2) with + | C.Sort s1, C.Sort s2 -> + NCicEnvironment.are_sorts_convertible ~test_eq_only s1 s2 + + | (C.Prod (name1,s1,t1), C.Prod(_,s2,t2)) -> + aux true context s1 s2 && + aux test_eq_only ((name1, C.Decl s1)::context) t1 t2 + | (C.Lambda (name1,s1,t1), C.Lambda(_,_,t2)) -> + if test_lambda_source then + aux test_eq_only context t1 t2 + else + (* thanks to inversion of well typedness, the source + * of these lambdas must be already convertible *) + aux test_eq_only ((name1, C.Decl s1)::context) t1 t2 + | (C.LetIn (name1,ty1,s1,t1), C.LetIn(_,ty2,s2,t2)) -> + aux test_eq_only context ty1 ty2 && + aux test_eq_only context s1 s2 && + aux test_eq_only ((name1, C.Def (s1,ty1))::context) t1 t2 + + | (C.Meta (n1,(s1, C.Irl _)), C.Meta (n2,(s2, C.Irl _))) + when n1 = n2 && s1 = s2 -> true + | (C.Meta (n1,(s1, l1)), C.Meta (n2,(s2, l2))) when n1 = n2 && + let l1 = NCicUtils.expand_local_context l1 in + let l2 = NCicUtils.expand_local_context l2 in + (try List.for_all2 + (fun t1 t2 -> aux test_eq_only context + (NCicSubstitution.lift s1 t1) + (NCicSubstitution.lift s2 t2)) + l1 l2 + with Invalid_argument "List.for_all2" -> + prerr_endline ("Meta " ^ string_of_int n1 ^ + " occurrs with local contexts of different lenght\n"^ + NCicPp.ppterm ~metasenv ~subst ~context t1 ^ " === " ^ + NCicPp.ppterm ~metasenv ~subst ~context t2); + assert false) -> true + + | C.Meta (n1,l1), _ -> + (try + let _,_,term,_ = NCicUtils.lookup_subst n1 subst in + let term = NCicSubstitution.subst_meta l1 term in + aux test_eq_only context term t2 + with NCicUtils.Subst_not_found _ -> false) + | _, C.Meta (n2,l2) -> + (try + let _,_,term,_ = NCicUtils.lookup_subst n2 subst in + let term = NCicSubstitution.subst_meta l2 term in + aux test_eq_only context t1 term + with NCicUtils.Subst_not_found _ -> false) + + | (C.Appl ((C.Const r1) as hd1::tl1), C.Appl (C.Const r2::tl2)) + when (Ref.eq r1 r2 && + List.length (E.get_relevance r1) >= List.length tl1) -> + let relevance = E.get_relevance r1 in +(* if the types were convertible the following optimization is sound + let relevance = match r1 with + | Ref.Ref (_,Ref.Con (_,_,lno)) -> + let _,relevance = HExtlib.split_nth lno relevance in + HExtlib.mk_list false lno @ relevance + | _ -> relevance + in +*) + (try + HExtlib.list_forall_default3_var + (fun t1 t2 b -> not b || aux true context t1 t2 ) + tl1 tl2 true relevance + with Invalid_argument _ -> false + | HExtlib.FailureAt fail -> + let relevance = + !get_relevance ~metasenv ~subst context hd1 tl1 in + let _,relevance = HExtlib.split_nth fail relevance in + let b,relevance = (match relevance with + | [] -> assert false + | b::tl -> b,tl) in + if (not b) then + let _,tl1 = HExtlib.split_nth (fail+1) tl1 in + let _,tl2 = HExtlib.split_nth (fail+1) tl2 in + try + HExtlib.list_forall_default3 + (fun t1 t2 b -> not b || aux true context t1 t2) + tl1 tl2 true relevance + with Invalid_argument _ -> false + else false) + + | (C.Appl (hd1::tl1), C.Appl (hd2::tl2)) -> + aux test_eq_only context hd1 hd2 && + let relevance = !get_relevance ~metasenv ~subst context hd1 tl1 in + (try + HExtlib.list_forall_default3 + (fun t1 t2 b -> not b || aux true context t1 t2) + tl1 tl2 true relevance + with Invalid_argument _ -> false) + + | (C.Match (Ref.Ref (_,Ref.Ind (_,tyno,_)) as ref1,outtype1,term1,pl1), + C.Match (ref2,outtype2,term2,pl2)) -> + let _,_,itl,_,_ = E.get_checked_indtys ref1 in + let _,_,ty,_ = List.nth itl tyno in + let rec remove_prods ~subst context ty = + let ty = whd ~subst context ty in + match ty with + | C.Sort _ -> ty + | C.Prod (name,so,ta) -> remove_prods ~subst ((name,(C.Decl so))::context) ta + | _ -> assert false + in + let is_prop = + match remove_prods ~subst [] ty with + | C.Sort C.Prop -> true + | _ -> false + in + Ref.eq ref1 ref2 && + aux test_eq_only context outtype1 outtype2 && + (is_prop || aux test_eq_only context term1 term2) && + (try List.for_all2 (aux test_eq_only context) pl1 pl2 + with Invalid_argument _ -> false) + | (C.Implicit _, _) | (_, C.Implicit _) -> assert false + | (_,_) -> false +;; + (* t1, t2 must be well-typed *) let are_convertible ~metasenv ~subst = let rec aux test_eq_only context t1 t2 = - let alpha_eq test_eq_only t1 t2 = - if t1 === t2 then - true - else - match (t1,t2) with - | (C.Sort (C.Type a), C.Sort (C.Type b)) when not test_eq_only -> - NCicEnvironment.universe_leq a b - | (C.Sort (C.Type a), C.Sort (C.Type b)) -> - NCicEnvironment.universe_eq a b - | (C.Sort C.Prop,C.Sort (C.Type _)) -> (not test_eq_only) - | (C.Sort C.Prop, C.Sort C.Prop) -> true - - | (C.Prod (name1,s1,t1), C.Prod(_,s2,t2)) -> - aux true context s1 s2 && - aux test_eq_only ((name1, C.Decl s1)::context) t1 t2 - | (C.Lambda (name1,s1,t1), C.Lambda(_,_,t2)) -> - (* thanks to inversion of well typedness, the source - * of these lambdas must be already convertible *) - aux test_eq_only ((name1, C.Decl s1)::context) t1 t2 - | (C.LetIn (name1,ty1,s1,t1), C.LetIn(_,ty2,s2,t2)) -> - aux test_eq_only context ty1 ty2 && - aux test_eq_only context s1 s2 && - aux test_eq_only ((name1, C.Def (s1,ty1))::context) t1 t2 - - | (C.Meta (n1,(s1, C.Irl _)), C.Meta (n2,(s2, C.Irl _))) - when n1 = n2 && s1 = s2 -> true - | (C.Meta (n1,(s1, l1)), C.Meta (n2,(s2, l2))) when n1 = n2 && - let l1 = NCicUtils.expand_local_context l1 in - let l2 = NCicUtils.expand_local_context l2 in - (try List.for_all2 - (fun t1 t2 -> aux test_eq_only context - (NCicSubstitution.lift s1 t1) - (NCicSubstitution.lift s2 t2)) - l1 l2 - with Invalid_argument "List.for_all2" -> - prerr_endline ("Meta " ^ string_of_int n1 ^ - " occurrs with local contexts of different lenght\n"^ - NCicPp.ppterm ~metasenv ~subst ~context t1 ^ " === " ^ - NCicPp.ppterm ~metasenv ~subst ~context t2); - assert false) -> true - - | C.Meta (n1,l1), _ -> - (try - let _,_,term,_ = NCicUtils.lookup_subst n1 subst in - let term = NCicSubstitution.subst_meta l1 term in - aux test_eq_only context term t2 - with NCicUtils.Subst_not_found _ -> false) - | _, C.Meta (n2,l2) -> - (try - let _,_,term,_ = NCicUtils.lookup_subst n2 subst in - let term = NCicSubstitution.subst_meta l2 term in - aux test_eq_only context t1 term - with NCicUtils.Subst_not_found _ -> false) - - | (C.Appl ((C.Const r1) as hd1::tl1), C.Appl (C.Const r2::tl2)) - when (Ref.eq r1 r2 && - List.length (E.get_relevance r1) >= List.length tl1) -> - let relevance = E.get_relevance r1 in - let relevance = match r1 with - | Ref.Ref (_,Ref.Con (_,_,lno)) -> - let _,relevance = HExtlib.split_nth lno relevance in - HExtlib.mk_list false lno @ relevance - | _ -> relevance - in - (try - HExtlib.list_forall_default3_var - (fun t1 t2 b -> not b || aux true context t1 t2 ) - tl1 tl2 true relevance - with Invalid_argument _ -> false - | HExtlib.FailureAt fail -> - let relevance = - !get_relevance ~metasenv ~subst context hd1 tl1 in - let _,relevance = HExtlib.split_nth fail relevance in - let b,relevance = (match relevance with - | [] -> assert false - | b::tl -> b,tl) in - if (not b) then - let _,tl1 = HExtlib.split_nth (fail+1) tl1 in - let _,tl2 = HExtlib.split_nth (fail+1) tl2 in - try - HExtlib.list_forall_default3 - (fun t1 t2 b -> not b || aux true context t1 t2) - tl1 tl2 true relevance - with Invalid_argument _ -> false - else false) - - | (C.Appl (hd1::tl1), C.Appl (hd2::tl2)) -> - aux test_eq_only context hd1 hd2 && - let relevance = !get_relevance ~metasenv ~subst context hd1 tl1 in - (try - HExtlib.list_forall_default3 - (fun t1 t2 b -> not b || aux true context t1 t2) - tl1 tl2 true relevance - with Invalid_argument _ -> false) - - | (C.Match (Ref.Ref (_,Ref.Ind (_,tyno,_)) as ref1,outtype1,term1,pl1), - C.Match (ref2,outtype2,term2,pl2)) -> - let _,_,itl,_,_ = E.get_checked_indtys ref1 in - let _,_,ty,_ = List.nth itl tyno in - let rec remove_prods ~subst context ty = - let ty = whd ~subst context ty in - match ty with - | C.Sort _ -> ty - | C.Prod (name,so,ta) -> remove_prods ~subst ((name,(C.Decl so))::context) ta - | _ -> assert false - in - let is_prop = - match remove_prods ~subst [] ty with - | C.Sort C.Prop -> true - | _ -> false - in - Ref.eq ref1 ref2 && - aux test_eq_only context outtype1 outtype2 && - (is_prop || aux test_eq_only context term1 term2) && - (try List.for_all2 (aux test_eq_only context) pl1 pl2 - with Invalid_argument _ -> false) - | (C.Implicit _, _) | (_, C.Implicit _) -> assert false - | (_,_) -> false + let alpha_eq test_eq_only = + alpha_eq ~test_lambda_source:false aux test_eq_only metasenv subst context in if alpha_eq test_eq_only t1 t2 then true @@ -354,8 +381,8 @@ let are_convertible ~metasenv ~subst = HExtlib.list_forall_default3 (fun t1 t2 b -> not b || - let t1 = RS.from_stack t1 in - let t2 = RS.from_stack t2 in + let t1 = RS.from_stack ~delta:max_int t1 in + let t2 = RS.from_stack ~delta:max_int t2 in convert_machines true (put_in_whd t1 t2)) s1 s2 true relevance with Invalid_argument _ -> false) || (not (norm1 && norm2) && convert_machines test_eq_only (small_delta_step m1 m2)) @@ -365,6 +392,13 @@ let are_convertible ~metasenv ~subst = aux false ;; +let alpha_eq metasenv subst = + let rec aux test_lambda_source context t1 t2 = + alpha_eq ~test_lambda_source aux true metasenv subst context t1 t2 + in + aux true +;; + let rec head_beta_reduce ~delta ~upto ~subst t l = match upto, t, l with | 0, C.Appl l1, _ -> C.Appl (l1 @ l) @@ -399,6 +433,7 @@ type machine = int * environment_item list * NCic.term * stack_item list let reduce_machine = R.reduce let from_stack = RS.from_stack +let from_env = RS.from_env let unwind = R.unwind let _ =