Mercurial > cpdt > repo
diff src/Intensional.v @ 204:cbf2f74a5130
Parts I want to keep compile with 8.2
author | Adam Chlipala <adamc@hcoop.net> |
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date | Fri, 06 Nov 2009 10:52:43 -0500 |
parents | 0198181d1b64 |
children | 2a34c4dc6a10 |
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--- a/src/Intensional.v Sun Jan 04 08:18:59 2009 -0500 +++ b/src/Intensional.v Fri Nov 06 10:52:43 2009 -0500 @@ -7,1078 +7,7 @@ * http://creativecommons.org/licenses/by-nc-nd/3.0/ *) -(* begin hide *) -Require Import Arith Bool String List Eqdep JMeq. - -Require Import Axioms Tactics DepList. - -Set Implicit Arguments. - -Infix "==" := JMeq (at level 70, no associativity). -(* end hide *) - - - (** %\chapter{Intensional Transformations}% *) -(** TODO: Prose for this chapter *) - - -(** * Closure Conversion *) - -Module Source. - Inductive type : Type := - | TNat : type - | Arrow : type -> type -> type. - - Notation "'Nat'" := TNat : source_scope. - Infix "-->" := Arrow (right associativity, at level 60) : source_scope. - - Open Scope source_scope. - Bind Scope source_scope with type. - Delimit Scope source_scope with source. - - Section vars. - Variable var : type -> Type. - - Inductive exp : type -> Type := - | Var : forall t, - var t - -> exp t - - | Const : nat -> exp Nat - | Plus : exp Nat -> exp Nat -> exp Nat - - | App : forall t1 t2, - exp (t1 --> t2) - -> exp t1 - -> exp t2 - | Abs : forall t1 t2, - (var t1 -> exp t2) - -> exp (t1 --> t2). - End vars. - - Definition Exp t := forall var, exp var t. - - Implicit Arguments Var [var t]. - Implicit Arguments Const [var]. - Implicit Arguments Plus [var]. - Implicit Arguments App [var t1 t2]. - Implicit Arguments Abs [var t1 t2]. - - Notation "# v" := (Var v) (at level 70) : source_scope. - - Notation "^ n" := (Const n) (at level 70) : source_scope. - Infix "+^" := Plus (left associativity, at level 79) : source_scope. - - Infix "@" := App (left associativity, at level 77) : source_scope. - Notation "\ x , e" := (Abs (fun x => e)) (at level 78) : source_scope. - Notation "\ ! , e" := (Abs (fun _ => e)) (at level 78) : source_scope. - - Bind Scope source_scope with exp. - - Definition zero : Exp Nat := fun _ => ^0. - Definition one : Exp Nat := fun _ => ^1. - Definition zpo : Exp Nat := fun _ => zero _ +^ one _. - Definition ident : Exp (Nat --> Nat) := fun _ => \x, #x. - Definition app_ident : Exp Nat := fun _ => ident _ @ zpo _. - Definition app : Exp ((Nat --> Nat) --> Nat --> Nat) := fun _ => - \f, \x, #f @ #x. - Definition app_ident' : Exp Nat := fun _ => app _ @ ident _ @ zpo _. - - Fixpoint typeDenote (t : type) : Set := - match t with - | Nat => nat - | t1 --> t2 => typeDenote t1 -> typeDenote t2 - end. - - Fixpoint expDenote t (e : exp typeDenote t) {struct e} : typeDenote t := - match e in (exp _ t) return (typeDenote t) with - | Var _ v => v - - | Const n => n - | Plus e1 e2 => expDenote e1 + expDenote e2 - - | App _ _ e1 e2 => (expDenote e1) (expDenote e2) - | Abs _ _ e' => fun x => expDenote (e' x) - end. - - Definition ExpDenote t (e : Exp t) := expDenote (e _). - - Section exp_equiv. - Variables var1 var2 : type -> Type. - - Inductive exp_equiv : list { t : type & var1 t * var2 t }%type -> forall t, exp var1 t -> exp var2 t -> Prop := - | EqVar : forall G t (v1 : var1 t) v2, - In (existT _ t (v1, v2)) G - -> exp_equiv G (#v1) (#v2) - - | EqConst : forall G n, - exp_equiv G (^n) (^n) - | EqPlus : forall G x1 y1 x2 y2, - exp_equiv G x1 x2 - -> exp_equiv G y1 y2 - -> exp_equiv G (x1 +^ y1) (x2 +^ y2) - - | EqApp : forall G t1 t2 (f1 : exp _ (t1 --> t2)) (x1 : exp _ t1) f2 x2, - exp_equiv G f1 f2 - -> exp_equiv G x1 x2 - -> exp_equiv G (f1 @ x1) (f2 @ x2) - | EqAbs : forall G t1 t2 (f1 : var1 t1 -> exp var1 t2) f2, - (forall v1 v2, exp_equiv (existT _ t1 (v1, v2) :: G) (f1 v1) (f2 v2)) - -> exp_equiv G (Abs f1) (Abs f2). - End exp_equiv. - - Axiom Exp_equiv : forall t (E : Exp t) var1 var2, - exp_equiv nil (E var1) (E var2). -End Source. - -Module Closed. - Inductive type : Type := - | TNat : type - | Arrow : type -> type -> type - | Code : type -> type -> type -> type - | Prod : type -> type -> type - | TUnit : type. - - Notation "'Nat'" := TNat : cc_scope. - Notation "'Unit'" := TUnit : cc_scope. - Infix "-->" := Arrow (right associativity, at level 60) : cc_scope. - Infix "**" := Prod (right associativity, at level 59) : cc_scope. - Notation "env @@ dom ---> ran" := (Code env dom ran) (no associativity, at level 62, dom at next level) : cc_scope. - - Bind Scope cc_scope with type. - Delimit Scope cc_scope with cc. - - Open Local Scope cc_scope. - - Section vars. - Variable var : type -> Set. - - Inductive exp : type -> Type := - | Var : forall t, - var t - -> exp t - - | Const : nat -> exp Nat - | Plus : exp Nat -> exp Nat -> exp Nat - - | App : forall dom ran, - exp (dom --> ran) - -> exp dom - -> exp ran - - | Pack : forall env dom ran, - exp (env @@ dom ---> ran) - -> exp env - -> exp (dom --> ran) - - | EUnit : exp Unit - - | Pair : forall t1 t2, - exp t1 - -> exp t2 - -> exp (t1 ** t2) - | Fst : forall t1 t2, - exp (t1 ** t2) - -> exp t1 - | Snd : forall t1 t2, - exp (t1 ** t2) - -> exp t2 - - | Let : forall t1 t2, - exp t1 - -> (var t1 -> exp t2) - -> exp t2. - - Section funcs. - Variable T : Type. - - Inductive funcs : Type := - | Main : T -> funcs - | Abs : forall env dom ran, - (var env -> var dom -> exp ran) - -> (var (env @@ dom ---> ran) -> funcs) - -> funcs. - End funcs. - - Definition prog t := funcs (exp t). - End vars. - - Implicit Arguments Var [var t]. - Implicit Arguments Const [var]. - Implicit Arguments EUnit [var]. - Implicit Arguments Fst [var t1 t2]. - Implicit Arguments Snd [var t1 t2]. - - Implicit Arguments Main [var T]. - Implicit Arguments Abs [var T env dom ran]. - - Notation "# v" := (Var v) (at level 70) : cc_scope. - - Notation "^ n" := (Const n) (at level 70) : cc_scope. - Infix "+^" := Plus (left associativity, at level 79) : cc_scope. - - Infix "@" := App (left associativity, at level 77) : cc_scope. - Infix "##" := Pack (no associativity, at level 71) : cc_scope. - - Notation "()" := EUnit : cc_scope. - - Notation "[ x1 , x2 ]" := (Pair x1 x2) (at level 73) : cc_scope. - Notation "#1 x" := (Fst x) (at level 72) : cc_scope. - Notation "#2 x" := (Snd x) (at level 72) : cc_scope. - - Notation "f <== \\ x , y , e ; fs" := - (Abs (fun x y => e) (fun f => fs)) - (right associativity, at level 80, e at next level) : cc_scope. - Notation "f <== \\ ! , y , e ; fs" := - (Abs (fun _ y => e) (fun f => fs)) - (right associativity, at level 80, e at next level) : cc_scope. - Notation "f <== \\ x , ! , e ; fs" := - (Abs (fun x _ => e) (fun f => fs)) - (right associativity, at level 80, e at next level) : cc_scope. - Notation "f <== \\ ! , ! , e ; fs" := - (Abs (fun _ _ => e) (fun f => fs)) - (right associativity, at level 80, e at next level) : cc_scope. - - Notation "x <- e1 ; e2" := (Let e1 (fun x => e2)) - (right associativity, at level 80, e1 at next level) : cc_scope. - - Bind Scope cc_scope with exp funcs prog. - - Fixpoint typeDenote (t : type) : Set := - match t with - | Nat => nat - | Unit => unit - | dom --> ran => typeDenote dom -> typeDenote ran - | t1 ** t2 => typeDenote t1 * typeDenote t2 - | env @@ dom ---> ran => typeDenote env -> typeDenote dom -> typeDenote ran - end%type. - - Fixpoint expDenote t (e : exp typeDenote t) {struct e} : typeDenote t := - match e in (exp _ t) return (typeDenote t) with - | Var _ v => v - - | Const n => n - | Plus e1 e2 => expDenote e1 + expDenote e2 - - | App _ _ f x => (expDenote f) (expDenote x) - | Pack _ _ _ f env => (expDenote f) (expDenote env) - - | EUnit => tt - - | Pair _ _ e1 e2 => (expDenote e1, expDenote e2) - | Fst _ _ e' => fst (expDenote e') - | Snd _ _ e' => snd (expDenote e') - - | Let _ _ e1 e2 => expDenote (e2 (expDenote e1)) - end. - - Fixpoint funcsDenote T (fs : funcs typeDenote T) : T := - match fs with - | Main v => v - | Abs _ _ _ e fs => - funcsDenote (fs (fun env arg => expDenote (e env arg))) - end. - - Definition progDenote t (p : prog typeDenote t) : typeDenote t := - expDenote (funcsDenote p). - - Definition Exp t := forall var, exp var t. - Definition Prog t := forall var, prog var t. - - Definition ExpDenote t (E : Exp t) := expDenote (E _). - Definition ProgDenote t (P : Prog t) := progDenote (P _). -End Closed. - -Import Source Closed. - -Section splice. - Open Local Scope cc_scope. - - Fixpoint spliceFuncs var T1 (fs : funcs var T1) - T2 (f : T1 -> funcs var T2) {struct fs} : funcs var T2 := - match fs with - | Main v => f v - | Abs _ _ _ e fs' => Abs e (fun x => spliceFuncs (fs' x) f) - end. -End splice. - -Notation "x <-- e1 ; e2" := (spliceFuncs e1 (fun x => e2)) - (right associativity, at level 80, e1 at next level) : cc_scope. - -Definition natvar (_ : Source.type) := nat. -Definition isfree := hlist (fun (_ : Source.type) => bool). - -Ltac maybe_destruct E := - match goal with - | [ x : _ |- _ ] => - match E with - | x => idtac - end - | _ => - match E with - | eq_nat_dec _ _ => idtac - end - end; destruct E. - -Ltac my_crush := - crush; repeat (match goal with - | [ x : (_ * _)%type |- _ ] => destruct x - | [ |- context[if ?B then _ else _] ] => maybe_destruct B - | [ _ : context[if ?B then _ else _] |- _ ] => maybe_destruct B - end; crush). - -Section isfree. - Import Source. - Open Local Scope source_scope. - - Fixpoint lookup_type (envT : list Source.type) (n : nat) {struct envT} - : isfree envT -> option Source.type := - match envT return (isfree envT -> _) with - | nil => fun _ => None - | first :: rest => fun fvs => - if eq_nat_dec n (length rest) - then match fvs with - | (true, _) => Some first - | (false, _) => None - end - else lookup_type rest n (snd fvs) - end. - - Implicit Arguments lookup_type [envT]. - - Notation ok := (fun (envT : list Source.type) (fvs : isfree envT) - (n : nat) (t : Source.type) - => lookup_type n fvs = Some t). - - Fixpoint wfExp (envT : list Source.type) (fvs : isfree envT) - t (e : Source.exp natvar t) {struct e} : Prop := - match e with - | Var t v => ok envT fvs v t - - | Const _ => True - | Plus e1 e2 => wfExp envT fvs e1 /\ wfExp envT fvs e2 - - | App _ _ e1 e2 => wfExp envT fvs e1 /\ wfExp envT fvs e2 - | Abs dom _ e' => wfExp (dom :: envT) (true ::: fvs) (e' (length envT)) - end. - - Implicit Arguments wfExp [envT t]. - - Theorem wfExp_weaken : forall t (e : exp natvar t) envT (fvs fvs' : isfree envT), - wfExp fvs e - -> (forall n t, ok _ fvs n t -> ok _ fvs' n t) - -> wfExp fvs' e. - Hint Extern 1 (lookup_type (envT := _ :: _) _ _ = Some _) => - simpl in *; my_crush. - - induction e; my_crush; eauto. - Defined. - - Fixpoint isfree_none (envT : list Source.type) : isfree envT := - match envT return (isfree envT) with - | nil => tt - | _ :: _ => (false, isfree_none _) - end. - - Implicit Arguments isfree_none [envT]. - - Fixpoint isfree_one (envT : list Source.type) (n : nat) {struct envT} : isfree envT := - match envT return (isfree envT) with - | nil => tt - | _ :: rest => - if eq_nat_dec n (length rest) - then (true, isfree_none) - else (false, isfree_one _ n) - end. - - Implicit Arguments isfree_one [envT]. - - Fixpoint isfree_merge (envT : list Source.type) : isfree envT -> isfree envT -> isfree envT := - match envT return (isfree envT -> isfree envT -> isfree envT) with - | nil => fun _ _ => tt - | _ :: _ => fun fv1 fv2 => (fst fv1 || fst fv2, isfree_merge _ (snd fv1) (snd fv2)) - end. - - Implicit Arguments isfree_merge [envT]. - - Fixpoint fvsExp t (e : exp natvar t) - (envT : list Source.type) {struct e} : isfree envT := - match e with - | Var _ n => isfree_one n - - | Const _ => isfree_none - | Plus e1 e2 => isfree_merge (fvsExp e1 envT) (fvsExp e2 envT) - - | App _ _ e1 e2 => isfree_merge (fvsExp e1 envT) (fvsExp e2 envT) - | Abs dom _ e' => snd (fvsExp (e' (length envT)) (dom :: envT)) - end. - - Lemma isfree_one_correct : forall t (v : natvar t) envT fvs, - ok envT fvs v t - -> ok envT (isfree_one (envT:=envT) v) v t. - induction envT; my_crush; eauto. - Defined. - - Lemma isfree_merge_correct1 : forall t (v : natvar t) envT fvs1 fvs2, - ok envT fvs1 v t - -> ok envT (isfree_merge (envT:=envT) fvs1 fvs2) v t. - induction envT; my_crush; eauto. - Defined. - - Hint Rewrite orb_true_r : cpdt. - - Lemma isfree_merge_correct2 : forall t (v : natvar t) envT fvs1 fvs2, - ok envT fvs2 v t - -> ok envT (isfree_merge (envT:=envT) fvs1 fvs2) v t. - induction envT; my_crush; eauto. - Defined. - - Hint Resolve isfree_one_correct isfree_merge_correct1 isfree_merge_correct2. - - Lemma fvsExp_correct : forall t (e : exp natvar t) - envT (fvs : isfree envT), wfExp fvs e - -> forall (fvs' : isfree envT), - (forall v t, ok envT (fvsExp e envT) v t -> ok envT fvs' v t) - -> wfExp fvs' e. - Hint Extern 1 (_ = _) => - match goal with - | [ H : lookup_type _ (fvsExp ?X ?Y) = _ |- _ ] => - destruct (fvsExp X Y); my_crush - end. - - induction e; my_crush; eauto. - Defined. - - Lemma lookup_type_unique : forall v t1 t2 envT (fvs1 fvs2 : isfree envT), - lookup_type v fvs1 = Some t1 - -> lookup_type v fvs2 = Some t2 - -> t1 = t2. - induction envT; my_crush; eauto. - Defined. - - Implicit Arguments lookup_type_unique [v t1 t2 envT fvs1 fvs2]. - - Hint Extern 2 (lookup_type _ _ = Some _) => - match goal with - | [ H1 : lookup_type ?v _ = Some _, - H2 : lookup_type ?v _ = Some _ |- _ ] => - (generalize (lookup_type_unique H1 H2); intro; subst) - || rewrite <- (lookup_type_unique H1 H2) - end. - - Lemma lookup_none : forall v t envT, - lookup_type (envT:=envT) v (isfree_none (envT:=envT)) = Some t - -> False. - induction envT; my_crush. - Defined. - - Hint Extern 2 (_ = _) => elimtype False; eapply lookup_none; eassumption. - - Lemma lookup_one : forall v' v t envT, - lookup_type (envT:=envT) v' (isfree_one (envT:=envT) v) = Some t - -> v' = v. - induction envT; my_crush. - Defined. - - Implicit Arguments lookup_one [v' v t envT]. - - Hint Extern 2 (lookup_type _ _ = Some _) => - match goal with - | [ H : lookup_type _ _ = Some _ |- _ ] => - generalize (lookup_one H); intro; subst - end. - - Lemma lookup_merge : forall v t envT (fvs1 fvs2 : isfree envT), - lookup_type v (isfree_merge fvs1 fvs2) = Some t - -> lookup_type v fvs1 = Some t - \/ lookup_type v fvs2 = Some t. - induction envT; my_crush. - Defined. - - Implicit Arguments lookup_merge [v t envT fvs1 fvs2]. - - Lemma lookup_bound : forall v t envT (fvs : isfree envT), - lookup_type v fvs = Some t - -> v < length envT. - Hint Resolve lt_S. - induction envT; my_crush; eauto. - Defined. - - Hint Resolve lookup_bound. - - Lemma lookup_bound_contra : forall t envT (fvs : isfree envT), - lookup_type (length envT) fvs = Some t - -> False. - intros; assert (length envT < length envT); eauto; crush. - Defined. - - Hint Resolve lookup_bound_contra. - - Lemma lookup_push_drop : forall v t t' envT fvs, - v < length envT - -> lookup_type (envT := t :: envT) v (true, fvs) = Some t' - -> lookup_type (envT := envT) v fvs = Some t'. - my_crush. - Defined. - - Lemma lookup_push_add : forall v t t' envT fvs, - lookup_type (envT := envT) v (snd fvs) = Some t' - -> lookup_type (envT := t :: envT) v fvs = Some t'. - my_crush; elimtype False; eauto. - Defined. - - Hint Resolve lookup_bound lookup_push_drop lookup_push_add. - - Theorem fvsExp_minimal : forall t (e : exp natvar t) - envT (fvs : isfree envT), wfExp fvs e - -> (forall v t, ok envT (fvsExp e envT) v t -> ok envT fvs v t). - Hint Extern 1 (_ = _) => - match goal with - | [ H : lookup_type _ (isfree_merge _ _) = Some _ |- _ ] => - destruct (lookup_merge H); clear H; eauto - end. - - induction e; my_crush; eauto. - Defined. - - Fixpoint ccType (t : Source.type) : Closed.type := - match t with - | Nat%source => Nat - | (dom --> ran)%source => ccType dom --> ccType ran - end%cc. - - Open Local Scope cc_scope. - - Fixpoint envType (envT : list Source.type) : isfree envT -> Closed.type := - match envT return (isfree envT -> _) with - | nil => fun _ => Unit - | t :: _ => fun tup => - if fst tup - then ccType t ** envType _ (snd tup) - else envType _ (snd tup) - end. - - Implicit Arguments envType [envT]. - - Fixpoint envOf (var : Closed.type -> Set) (envT : list Source.type) {struct envT} - : isfree envT -> Set := - match envT return (isfree envT -> _) with - | nil => fun _ => unit - | first :: rest => fun fvs => - match fvs with - | (true, fvs') => (var (ccType first) * envOf var rest fvs')%type - | (false, fvs') => envOf var rest fvs' - end - end. - - Implicit Arguments envOf [envT]. - - Notation "var <| to" := (match to with - | None => unit - | Some t => var (ccType t) - end) (no associativity, at level 70). - - Fixpoint lookup (var : Closed.type -> Set) (envT : list Source.type) : - forall (n : nat) (fvs : isfree envT), envOf var fvs -> var <| lookup_type n fvs := - match envT return (forall (n : nat) (fvs : isfree envT), envOf var fvs - -> var <| lookup_type n fvs) with - | nil => fun _ _ _ => tt - | first :: rest => fun n fvs => - match (eq_nat_dec n (length rest)) as Heq return - (envOf var (envT := first :: rest) fvs - -> var <| (if Heq - then match fvs with - | (true, _) => Some first - | (false, _) => None - end - else lookup_type n (snd fvs))) with - | left _ => - match fvs return (envOf var (envT := first :: rest) fvs - -> var <| (match fvs with - | (true, _) => Some first - | (false, _) => None - end)) with - | (true, _) => fun env => fst env - | (false, _) => fun _ => tt - end - | right _ => - match fvs return (envOf var (envT := first :: rest) fvs - -> var <| (lookup_type n (snd fvs))) with - | (true, fvs') => fun env => lookup var rest n fvs' (snd env) - | (false, fvs') => fun env => lookup var rest n fvs' env - end - end - end. - - Theorem lok : forall var n t envT (fvs : isfree envT), - lookup_type n fvs = Some t - -> var <| lookup_type n fvs = var (ccType t). - crush. - Defined. -End isfree. - -Implicit Arguments lookup_type [envT]. -Implicit Arguments lookup [envT fvs]. -Implicit Arguments wfExp [t envT]. -Implicit Arguments envType [envT]. -Implicit Arguments envOf [envT]. -Implicit Arguments lok [var n t envT fvs]. - -Section lookup_hints. - Hint Resolve lookup_bound_contra. - - Hint Resolve lookup_bound_contra. - - Lemma lookup_type_push : forall t' envT (fvs1 fvs2 : isfree envT) b1 b2, - (forall (n : nat) (t : Source.type), - lookup_type (envT := t' :: envT) n (b1, fvs1) = Some t -> - lookup_type (envT := t' :: envT) n (b2, fvs2) = Some t) - -> (forall (n : nat) (t : Source.type), - lookup_type n fvs1 = Some t -> - lookup_type n fvs2 = Some t). - intros until b2; intro H; intros n t; - generalize (H n t); my_crush; elimtype False; eauto. - Defined. - - Lemma lookup_type_push_contra : forall t' envT (fvs1 fvs2 : isfree envT), - (forall (n : nat) (t : Source.type), - lookup_type (envT := t' :: envT) n (true, fvs1) = Some t -> - lookup_type (envT := t' :: envT) n (false, fvs2) = Some t) - -> False. - intros until fvs2; intro H; generalize (H (length envT) t'); my_crush. - Defined. -End lookup_hints. - -Section packing. - Open Local Scope cc_scope. - - Hint Resolve lookup_type_push lookup_type_push_contra. - - Definition packExp (var : Closed.type -> Set) (envT : list Source.type) - (fvs1 fvs2 : isfree envT) - : (forall n t, lookup_type n fvs1 = Some t -> lookup_type n fvs2 = Some t) - -> envOf var fvs2 -> exp var (envType fvs1). - refine (fix packExp (var : Closed.type -> Set) (envT : list Source.type) {struct envT} - : forall fvs1 fvs2 : isfree envT, - (forall n t, lookup_type n fvs1 = Some t -> lookup_type n fvs2 = Some t) - -> envOf var fvs2 -> exp var (envType fvs1) := - match envT return (forall fvs1 fvs2 : isfree envT, - (forall n t, lookup_type n fvs1 = Some t -> lookup_type n fvs2 = Some t) - -> envOf var fvs2 - -> exp var (envType fvs1)) with - | nil => fun _ _ _ _ => () - | first :: rest => fun fvs1 => - match fvs1 return (forall fvs2 : isfree (first :: rest), - (forall n t, lookup_type (envT := first :: rest) n fvs1 = Some t - -> lookup_type n fvs2 = Some t) - -> envOf var fvs2 - -> exp var (envType (envT := first :: rest) fvs1)) with - | (false, fvs1') => fun fvs2 => - match fvs2 return ((forall n t, lookup_type (envT := first :: rest) n (false, fvs1') = Some t - -> lookup_type (envT := first :: rest) n fvs2 = Some t) - -> envOf (envT := first :: rest) var fvs2 - -> exp var (envType (envT := first :: rest) (false, fvs1'))) with - | (false, fvs2') => fun Hmin env => - packExp var _ fvs1' fvs2' _ env - | (true, fvs2') => fun Hmin env => - packExp var _ fvs1' fvs2' _ (snd env) - end - | (true, fvs1') => fun fvs2 => - match fvs2 return ((forall n t, lookup_type (envT := first :: rest) n (true, fvs1') = Some t - -> lookup_type (envT := first :: rest) n fvs2 = Some t) - -> envOf (envT := first :: rest) var fvs2 - -> exp var (envType (envT := first :: rest) (true, fvs1'))) with - | (false, fvs2') => fun Hmin env => - False_rect _ _ - | (true, fvs2') => fun Hmin env => - [#(fst env), packExp var _ fvs1' fvs2' _ (snd env)] - end - end - end); eauto. - Defined. - - Hint Resolve fvsExp_correct fvsExp_minimal. - Hint Resolve lookup_push_drop lookup_bound lookup_push_add. - - Implicit Arguments packExp [var envT]. - - Fixpoint unpackExp (var : Closed.type -> Set) t (envT : list Source.type) {struct envT} - : forall fvs : isfree envT, - exp var (envType fvs) - -> (envOf var fvs -> exp var t) -> exp var t := - match envT return (forall fvs : isfree envT, - exp var (envType fvs) - -> (envOf var fvs -> exp var t) -> exp var t) with - | nil => fun _ _ f => f tt - | first :: rest => fun fvs => - match fvs return (exp var (envType (envT := first :: rest) fvs) - -> (envOf var (envT := first :: rest) fvs -> exp var t) - -> exp var t) with - | (false, fvs') => fun p f => - unpackExp rest fvs' p f - | (true, fvs') => fun p f => - x <- #1 p; - unpackExp rest fvs' (#2 p) - (fun env => f (x, env)) - end - end. - - Implicit Arguments unpackExp [var t envT fvs]. - - Theorem wfExp_lax : forall t t' envT (fvs : isfree envT) (e : Source.exp natvar t), - wfExp (envT := t' :: envT) (true, fvs) e - -> wfExp (envT := t' :: envT) (true, snd (fvsExp e (t' :: envT))) e. - Hint Extern 1 (_ = _) => - match goal with - | [ H : lookup_type _ (fvsExp ?X ?Y) = _ |- _ ] => - destruct (fvsExp X Y); my_crush - end. - eauto. - Defined. - - Implicit Arguments wfExp_lax [t t' envT fvs e]. - - Lemma inclusion : forall t t' envT fvs (e : Source.exp natvar t), - wfExp (envT := t' :: envT) (true, fvs) e - -> (forall n t, lookup_type n (snd (fvsExp e (t' :: envT))) = Some t - -> lookup_type n fvs = Some t). - eauto. - Defined. - - Implicit Arguments inclusion [t t' envT fvs e]. - - Definition env_prog var t envT (fvs : isfree envT) := - funcs var (envOf var fvs -> Closed.exp var t). - - Implicit Arguments env_prog [envT]. - - Import Source. - Open Local Scope cc_scope. - - Definition proj1 A B (pf : A /\ B) : A := - let (x, _) := pf in x. - Definition proj2 A B (pf : A /\ B) : B := - let (_, y) := pf in y. - - Fixpoint ccExp var t (e : Source.exp natvar t) - (envT : list Source.type) (fvs : isfree envT) - {struct e} : wfExp fvs e -> env_prog var (ccType t) fvs := - match e in (Source.exp _ t) return (wfExp fvs e -> env_prog var (ccType t) fvs) with - | Const n => fun _ => Main (fun _ => ^n) - | Plus e1 e2 => fun wf => - n1 <-- ccExp var e1 _ fvs (proj1 wf); - n2 <-- ccExp var e2 _ fvs (proj2 wf); - Main (fun env => n1 env +^ n2 env) - - | Var _ n => fun wf => - Main (fun env => #(match lok wf in _ = T return T with - | refl_equal => lookup var n env - end)) - - | App _ _ f x => fun wf => - f' <-- ccExp var f _ fvs (proj1 wf); - x' <-- ccExp var x _ fvs (proj2 wf); - Main (fun env => f' env @ x' env) - - | Abs dom _ b => fun wf => - b' <-- ccExp var (b (length envT)) (dom :: envT) _ (wfExp_lax wf); - f <== \\env, arg, unpackExp (#env) (fun env => b' (arg, env)); - Main (fun env => #f ## - packExp - (snd (fvsExp (b (length envT)) (dom :: envT))) - fvs (inclusion wf) env) - end. -End packing. - -Implicit Arguments packExp [var envT]. -Implicit Arguments unpackExp [var t envT fvs]. - -Implicit Arguments ccExp [var t envT]. - -Fixpoint map_funcs var T1 T2 (f : T1 -> T2) (fs : funcs var T1) {struct fs} - : funcs var T2 := - match fs with - | Main v => Main (f v) - | Abs _ _ _ e fs' => Abs e (fun x => map_funcs f (fs' x)) - end. - -Definition CcExp' t (E : Source.Exp t) (Hwf : wfExp (envT := nil) tt (E _)) : Prog (ccType t) := - fun _ => map_funcs (fun f => f tt) (ccExp (E _) (envT := nil) tt Hwf). - - -(** ** Examples *) - -Open Local Scope source_scope. - -Definition ident : Source.Exp (Nat --> Nat) := fun _ => \x, #x. -Theorem ident_ok : wfExp (envT := nil) tt (ident _). - crush. -Defined. -Eval compute in CcExp' ident ident_ok. -Eval compute in ProgDenote (CcExp' ident ident_ok). - -Definition app_ident : Source.Exp Nat := fun _ => ident _ @ ^0. -Theorem app_ident_ok : wfExp (envT := nil) tt (app_ident _). - crush. -Defined. -Eval compute in CcExp' app_ident app_ident_ok. -Eval compute in ProgDenote (CcExp' app_ident app_ident_ok). - -Definition first : Source.Exp (Nat --> Nat --> Nat) := fun _ => - \x, \y, #x. -Theorem first_ok : wfExp (envT := nil) tt (first _). - crush. -Defined. -Eval compute in CcExp' first first_ok. -Eval compute in ProgDenote (CcExp' first first_ok). - -Definition app_first : Source.Exp Nat := fun _ => first _ @ ^1 @ ^0. -Theorem app_first_ok : wfExp (envT := nil) tt (app_first _). - crush. -Defined. -Eval compute in CcExp' app_first app_first_ok. -Eval compute in ProgDenote (CcExp' app_first app_first_ok). - - -(** ** Correctness *) - -Section spliceFuncs_correct. - Variables T1 T2 : Type. - Variable f : T1 -> funcs typeDenote T2. - - Theorem spliceFuncs_correct : forall fs, - funcsDenote (spliceFuncs fs f) - = funcsDenote (f (funcsDenote fs)). - induction fs; crush. - Qed. -End spliceFuncs_correct. - - -Notation "var <| to" := (match to return Set with - | None => unit - | Some t => var (ccType t) - end) (no associativity, at level 70). - -Section packing_correct. - Fixpoint makeEnv (envT : list Source.type) : forall (fvs : isfree envT), - Closed.typeDenote (envType fvs) - -> envOf Closed.typeDenote fvs := - match envT return (forall (fvs : isfree envT), - Closed.typeDenote (envType fvs) - -> envOf Closed.typeDenote fvs) with - | nil => fun _ _ => tt - | first :: rest => fun fvs => - match fvs return (Closed.typeDenote (envType (envT := first :: rest) fvs) - -> envOf (envT := first :: rest) Closed.typeDenote fvs) with - | (false, fvs') => fun env => makeEnv rest fvs' env - | (true, fvs') => fun env => (fst env, makeEnv rest fvs' (snd env)) - end - end. - - Implicit Arguments makeEnv [envT fvs]. - - Theorem unpackExp_correct : forall t (envT : list Source.type) (fvs : isfree envT) - (e1 : Closed.exp Closed.typeDenote (envType fvs)) - (e2 : envOf Closed.typeDenote fvs -> Closed.exp Closed.typeDenote t), - Closed.expDenote (unpackExp e1 e2) - = Closed.expDenote (e2 (makeEnv (Closed.expDenote e1))). - induction envT; my_crush. - Qed. - - Lemma lookup_type_more : forall v2 envT (fvs : isfree envT) t b v, - (v2 = length envT -> False) - -> lookup_type v2 (envT := t :: envT) (b, fvs) = v - -> lookup_type v2 fvs = v. - my_crush. - Qed. - - Lemma lookup_type_less : forall v2 t envT (fvs : isfree (t :: envT)) v, - (v2 = length envT -> False) - -> lookup_type v2 (snd fvs) = v - -> lookup_type v2 (envT := t :: envT) fvs = v. - my_crush. - Qed. - - Hint Resolve lookup_bound_contra. - - Lemma lookup_bound_contra_eq : forall t envT (fvs : isfree envT) v, - lookup_type v fvs = Some t - -> v = length envT - -> False. - my_crush; elimtype False; eauto. - Qed. - - Lemma lookup_type_inner : forall t t' envT v t'' (fvs : isfree envT) e, - wfExp (envT := t' :: envT) (true, fvs) e - -> lookup_type v (snd (fvsExp (t := t) e (t' :: envT))) = Some t'' - -> lookup_type v fvs = Some t''. - Hint Resolve lookup_bound_contra_eq fvsExp_minimal - lookup_type_more lookup_type_less. - Hint Extern 2 (Some _ = Some _) => elimtype False. - - eauto 6. - Qed. - - Lemma cast_irrel : forall T1 T2 x (H1 H2 : T1 = T2), - match H1 in _ = T return T with - | refl_equal => x - end - = match H2 in _ = T return T with - | refl_equal => x - end. - intros; generalize H1; crush; - repeat match goal with - | [ |- context[match ?pf with refl_equal => _ end] ] => - rewrite (UIP_refl _ _ pf) - end; - reflexivity. - Qed. - - Hint Immediate cast_irrel. - - Hint Extern 3 (_ == _) => - match goal with - | [ |- context[False_rect _ ?H] ] => - apply False_rect; exact H - end. - - Theorem packExp_correct : forall v t envT (fvs1 fvs2 : isfree envT) - Hincl env, - lookup_type v fvs1 = Some t - -> lookup Closed.typeDenote v env - == lookup Closed.typeDenote v - (makeEnv (Closed.expDenote - (packExp fvs1 fvs2 Hincl env))). - induction envT; my_crush. - Qed. -End packing_correct. - -Implicit Arguments packExp_correct [v envT fvs1]. -Implicit Arguments lookup_type_inner [t t' envT v t'' fvs e]. -Implicit Arguments inclusion [t t' envT fvs e]. - -Lemma typeDenote_same : forall t, - Source.typeDenote t = Closed.typeDenote (ccType t). - induction t; crush. -Qed. - -Hint Resolve typeDenote_same. - -Fixpoint lr (t : Source.type) : Source.typeDenote t -> Closed.typeDenote (ccType t) -> Prop := - match t return Source.typeDenote t -> Closed.typeDenote (ccType t) -> Prop with - | Nat => @eq nat - | dom --> ran => fun f1 f2 => - forall x1 x2, lr dom x1 x2 - -> lr ran (f1 x1) (f2 x2) - end. - -Theorem ccExp_correct : forall t G - (e1 : Source.exp Source.typeDenote t) - (e2 : Source.exp natvar t), - exp_equiv G e1 e2 - -> forall (envT : list Source.type) (fvs : isfree envT) - (env : envOf Closed.typeDenote fvs) (wf : wfExp fvs e2), - (forall t (v1 : Source.typeDenote t) (v2 : natvar t), - In (existT _ _ (v1, v2)) G - -> v2 < length envT) - -> (forall t (v1 : Source.typeDenote t) (v2 : natvar t), - In (existT _ _ (v1, v2)) G - -> forall pf, - lr t v1 (match lok pf in _ = T return T with - | refl_equal => lookup Closed.typeDenote v2 env - end)) - -> lr t (Source.expDenote e1) (Closed.expDenote (funcsDenote (ccExp e2 fvs wf) env)). - - Hint Rewrite spliceFuncs_correct unpackExp_correct : cpdt. - Hint Resolve packExp_correct lookup_type_inner. - - induction 1; crush; - match goal with - | [ IH : _, Hlr : lr ?T ?X1 ?X2, ENV : list Source.type, F2 : natvar _ -> _ |- _ ] => - apply (IH X1 (length ENV) (T :: ENV) (true, snd (fvsExp (F2 (length ENV)) (T :: ENV)))) - end; crush; - match goal with - | [ Hlt : forall t v1 v2, _ -> _ < _, Hin : In _ _ |- _ ] => - solve [ generalize (Hlt _ _ _ Hin); crush ] - | [ |- context[match ?pf with refl_equal => _ end] ] => generalize pf - end; simpl; - match goal with - | [ |- context[if ?E then _ else _] ] => destruct E - end; intuition; subst; - match goal with - | [ |- context[match ?pf with refl_equal => _ end] ] => rewrite (UIP_refl _ _ pf); assumption - | [ Hlt : forall t v1 v2, _ -> _ < _, Hin : In (existT _ _ (_, length _)) _ |- _ ] => - generalize (Hlt _ _ _ Hin); crush - | [ HG : _, Hin : In _ _, wf : wfExp _ _, pf : _ = Some _, - fvs : isfree _, env : envOf _ _ |- _ ] => - generalize (HG _ _ _ Hin (lookup_type_inner wf pf)); clear_all; - repeat match goal with - | [ |- context[match ?pf with refl_equal => _ end] ] => generalize pf - end; simpl; - generalize (packExp_correct _ fvs (inclusion wf) env pf); simpl; - match goal with - | [ |- ?X == ?Y -> _ ] => - generalize X Y - end; - rewrite pf; rewrite (lookup_type_inner wf pf); - intros lhs rhs Heq; intros; - repeat match goal with - | [ H : _ = _ |- _ ] => rewrite (UIP_refl _ _ H) in * - end; - rewrite <- Heq; assumption - end. -Qed. - - -(** * Parametric version *) - -Section wf. - Lemma Exp_wf' : forall G t (e1 e2 : Source.exp natvar t), - exp_equiv G e1 e2 - -> forall envT (fvs : isfree envT), - (forall t (v1 v2 : natvar t), In (existT _ _ (v1, v2)) G - -> lookup_type v1 fvs = Some t) - -> wfExp fvs e1. - Hint Extern 3 (Some _ = Some _) => elimtype False; eapply lookup_bound_contra; eauto. - - induction 1; crush; eauto; - match goal with - | [ H : _, envT : list Source.type |- _ ] => - apply H with (length envT); my_crush; eauto - end. - Qed. - - Theorem Exp_wf : forall t (E : Source.Exp t), - wfExp (envT := nil) tt (E _). - Hint Resolve Exp_equiv. - - intros; eapply Exp_wf'; crush. - Qed. -End wf. - -Definition CcExp t (E : Source.Exp t) : Prog (ccType t) := - CcExp' E (Exp_wf E). - -Lemma map_funcs_correct : forall T1 T2 (f : T1 -> T2) (fs : funcs Closed.typeDenote T1), - funcsDenote (map_funcs f fs) = f (funcsDenote fs). - induction fs; crush. -Qed. - -Theorem CcExp_correct : forall (E : Source.Exp Nat), - Source.ExpDenote E - = ProgDenote (CcExp E). - Hint Rewrite map_funcs_correct : cpdt. - - unfold Source.ExpDenote, ProgDenote, CcExp, CcExp', progDenote; crush; - apply (ccExp_correct - (G := nil) - (e1 := E _) - (e2 := E _) - (Exp_equiv _ _ _) - nil - tt - tt); crush. -Qed. +(** TODO: This chapter! (Old version was too complicated) *)