(*********************************************************************************************************************************)
(* ProgrammingLanguage *)
(* *)
-(* Basic assumptions about programming languages . *)
+(* Basic assumptions about programming languages. *)
(* *)
(*********************************************************************************************************************************)
Require Import Subcategories_ch7_1.
Require Import NaturalTransformations_ch7_4.
Require Import NaturalIsomorphisms_ch7_5.
+Require Import BinoidalCategories.
+Require Import PreMonoidalCategories.
Require Import MonoidalCategories_ch7_8.
Require Import Coherence_ch7_8.
Require Import Enrichment_ch2_8.
Require Import FunctorCategories_ch7_7.
Require Import NaturalDeduction.
-Require Import NaturalDeductionCategory.
-Require Import FreydCategories.
-
-Require Import Reification.
-Require Import GeneralizedArrow.
-Require Import GeneralizedArrowFromReification.
-Require Import ReificationFromGeneralizedArrow.
-
-(*
- * Everything in the rest of this section is just groundwork meant to
- * build up to the definition of the ProgrammingLanguage class, which
- * appears at the end of the section. References to "the instance"
- * mean instances of that class. Think of this section as being one
- * big Class { ... } definition, except that we declare most of the
- * stuff outside the curly brackets in order to take advantage of
- * Coq's section mechanism.
- *)
Section Programming_Language.
Context {T : Type}. (* types of the language *)
- Context (Judg : Type).
- Context (sequent : Tree ??T -> Tree ??T -> Judg).
+ Definition PLJudg := (Tree ??T) * (Tree ??T).
+ Definition sequent := @pair (Tree ??T) (Tree ??T).
Notation "cs |= ss" := (sequent cs ss) : pl_scope.
- (* Because of term irrelevance we need only store the *erased* (def
- * 4.4) trees; for this reason there is no Coq type directly
- * corresponding to productions $e$ and $x$ of 4.1.1, and TreeOT can
- * be used for productions $\Gamma$ and $\Sigma$ *)
- (* to do: sequent calculus equals natural deduction over sequents, theorem equals sequent with null antecedent, *)
-
- Context {Rule : Tree ??Judg -> Tree ??Judg -> Type}.
+ Context {Rule : Tree ??PLJudg -> Tree ??PLJudg -> Type}.
Notation "H /⋯⋯/ C" := (ND Rule H C) : pl_scope.
Open Scope nd_scope.
Open Scope pl_scope.
- (*
- *
- * Note that from this abstract interface, the terms (expressions)
- * in the proof are not accessible at all; they don't need to be --
- * so long as we have access to the equivalence relation upon
- * proof-conclusions. Moreover, hiding the expressions actually
- * makes the encoding in CiC work out easier for two reasons:
- *
- * 1. Because the denotation function is provided a proof rather
- * than a term, it is a total function (the denotation function is
- * often undefined for ill-typed terms).
- *
- * 2. We can define arr_composition of proofs without having to know how
- * to compose expressions. The latter task is left up to the client
- * function which extracts an expression from a completed proof.
- *
- * This also means that we don't need an explicit proof obligation for 4.1.2.
- *)
Class ProgrammingLanguage :=
- { pl_eqv : @ND_Relation Judg Rule where "pf1 === pf2" := (@ndr_eqv _ _ pl_eqv _ _ pf1 pf2)
- ; pl_tsr :> @TreeStructuralRules Judg Rule T sequent
- ; pl_sc :> @SequentCalculus Judg Rule _ sequent
- ; pl_subst :> @CutRule Judg Rule _ sequent pl_eqv pl_sc
- ; pl_sequent_join :> @SequentExpansion Judg Rule T sequent pl_eqv pl_sc pl_subst
+ { pl_eqv0 :> @ND_Relation PLJudg Rule
+ ; pl_snd :> @SequentND PLJudg Rule _ sequent
+ ; pl_cnd :> @ContextND PLJudg Rule T sequent pl_snd
+ ; pl_eqv1 :> @SequentND_Relation PLJudg Rule _ sequent pl_snd pl_eqv0
+ ; pl_eqv :> @ContextND_Relation PLJudg Rule _ sequent pl_snd pl_cnd pl_eqv0 pl_eqv1
}.
Notation "pf1 === pf2" := (@ndr_eqv _ _ pl_eqv _ _ pf1 pf2) : temporary_scope3.
-
- Section LanguageCategory.
-
- Context (PL:ProgrammingLanguage).
-
- (* category of judgments in a fixed type/coercion context *)
- Definition Judgments_cartesian := @Judgments_Category_CartesianCat _ Rule pl_eqv.
-
- Definition JudgmentsL := Judgments_cartesian.
-
- Definition identityProof t : [] ~~{JudgmentsL}~~> [t |= t].
- unfold hom; simpl.
- apply nd_seq_reflexive.
- Defined.
-
- Definition cutProof a b c : [a |= b],,[b |= c] ~~{JudgmentsL}~~> [a |= c].
- unfold hom; simpl.
- apply pl_subst.
- Defined.
-
- Definition TypesL : ECategory JudgmentsL (Tree ??T) (fun x y => [x|=y]).
- refine
- {| eid := identityProof
- ; ecomp := cutProof
- |}; intros.
- apply MonoidalCat_all_central.
- apply MonoidalCat_all_central.
- unfold identityProof; unfold cutProof; simpl.
- apply nd_cut_left_identity.
- unfold identityProof; unfold cutProof; simpl.
- apply nd_cut_right_identity.
- unfold identityProof; unfold cutProof; simpl.
- symmetry.
- apply nd_cut_associativity.
- Defined.
-
- Definition Types_first c : EFunctor TypesL TypesL (fun x => x,,c ).
- refine {| efunc := fun x y => (nd_rule (@se_expand_right _ _ _ _ _ _ _ (@pl_sequent_join PL) c x y)) |}.
- intros; apply MonoidalCat_all_central.
- intros. unfold ehom. unfold hom. unfold identityProof. unfold eid. simpl. unfold identityProof.
- apply se_reflexive_right.
- intros. unfold ehom. unfold comp. simpl. unfold cutProof.
- rewrite <- (@ndr_prod_preserves_comp _ _ pl_eqv _ _ [#se_expand_right _ c#] _ _ (nd_id1 (b|=c0))
- _ (nd_id1 (a,,c |= b,,c)) _ [#se_expand_right _ c#]).
- setoid_rewrite (@ndr_comp_right_identity _ _ pl_eqv _ [a,, c |= b,, c]).
- setoid_rewrite (@ndr_comp_left_identity _ _ pl_eqv [b |= c0]).
- apply se_cut_right.
- Defined.
-
- Definition Types_second c : EFunctor TypesL TypesL (fun x => c,,x).
- eapply Build_EFunctor.
- instantiate (1:=(fun x y => (nd_rule (@se_expand_left _ _ _ _ _ _ _ (@pl_sequent_join PL) c x y)))).
- intros; apply MonoidalCat_all_central.
- intros. unfold ehom. unfold hom. unfold identityProof. unfold eid. simpl. unfold identityProof.
- apply se_reflexive_left.
- intros. unfold ehom. unfold comp. simpl. unfold cutProof.
- rewrite <- (@ndr_prod_preserves_comp _ _ pl_eqv _ _ [#se_expand_left _ c#] _ _ (nd_id1 (b|=c0))
- _ (nd_id1 (c,,a |= c,,b)) _ [#se_expand_left _ c#]).
- setoid_rewrite (@ndr_comp_right_identity _ _ pl_eqv _ [c,,a |= c,,b]).
- setoid_rewrite (@ndr_comp_left_identity _ _ pl_eqv [b |= c0]).
- apply se_cut_left.
- Defined.
-
- Definition Types_binoidal : BinoidalCat TypesL (@T_Branch _).
- refine
- {| bin_first := Types_first
- ; bin_second := Types_second
- |}.
- Defined.
-
- Definition Types_PreMonoidal : PreMonoidalCat Types_binoidal [].
- admit.
- Defined.
-
- Definition TypesEnrichedInJudgments : Enrichment.
- refine {| enr_c := TypesL |}.
- Defined.
-
- Structure HasProductTypes :=
- {
- }.
-
- (* need to prove that if we have cartesian tuples we have cartesian contexts *)
- Definition LanguagesWithProductsAreSMME : HasProductTypes -> SurjectiveMonicMonoidalEnrichment TypesEnrichedInJudgments.
- admit.
- Defined.
-
- End LanguageCategory.
-
- Structure ProgrammingLanguageSMME :=
- { plsmme_pl : ProgrammingLanguage
- ; plsmme_smme : SurjectiveMonicMonoidalEnrichment (TypesEnrichedInJudgments plsmme_pl)
- }.
- Coercion plsmme_pl : ProgrammingLanguageSMME >-> ProgrammingLanguage.
- Coercion plsmme_smme : ProgrammingLanguageSMME >-> SurjectiveMonicMonoidalEnrichment.
-
- Section ArrowInLanguage.
- Context (Host:ProgrammingLanguageSMME).
- Context `(CC:CartesianCat (me_mon Host)).
- Context `(K:@ECategory _ _ _ _ _ _ (@car_mn _ _ _ _ _ _ _ CC) C Kehom).
- Context `(pmc:PreMonoidalCat K bobj mobj (@one _ _ _ (cartesian_terminal C))).
- (* FIXME *)
- (*
- Definition ArrowInProgrammingLanguage :=
- @FreydCategory _ _ _ _ _ _ (@car_mn _ _ _ _ _ _ _ CC) _ _ _ _ pmc.
- *)
- End ArrowInLanguage.
-
- Section GArrowInLanguage.
- Context (Guest:ProgrammingLanguageSMME).
- Context (Host :ProgrammingLanguageSMME).
- Definition GeneralizedArrowInLanguage := GeneralizedArrow Guest Host.
-
- (* FIXME
- Definition ArrowsAreGeneralizedArrows : ArrowInProgrammingLanguage -> GeneralizedArrowInLanguage.
- *)
- Definition TwoLevelLanguage := Reification Guest Host (me_i Host).
-
- Context (GuestHost:TwoLevelLanguage).
-
- Definition FlatObject (x:TypesL Host) :=
- forall y1 y2, not ((reification_r_obj GuestHost y1 y2)=x).
-
- Definition FlatSubCategory := FullSubcategory (TypesL Host) FlatObject.
-
- Section Flattening.
-
- Context (F:Retraction (TypesL Host) FlatSubCategory).
- Definition FlatteningOfReification := garrow_from_reification Guest Host GuestHost >>>> F.
- Lemma FlatteningIsNotDestructive :
- FlatteningOfReification >>>> retraction_retraction F >>>> RepresentableFunctor _ (me_i Host) ~~~~ GuestHost.
- admit.
- Qed.
-
- End Flattening.
-
- End GArrowInLanguage.
-
- Inductive NLevelLanguage : nat -> ProgrammingLanguageSMME -> Type :=
- | NLevelLanguage_zero : forall lang, NLevelLanguage O lang
- | NLevelLanguage_succ : forall (L1 L2:ProgrammingLanguageSMME) n,
- TwoLevelLanguage L1 L2 -> NLevelLanguage n L1 -> NLevelLanguage (S n) L2.
-
- Definition OmegaLevelLanguage : Type :=
- { f : nat -> ProgrammingLanguageSMME
- & forall n, TwoLevelLanguage (f n) (f (S n)) }.
-
- Close Scope temporary_scope3.
- Close Scope pl_scope.
- Close Scope nd_scope.
- Close Scope pf_scope.
+ Coercion pl_eqv : ProgrammingLanguage >-> ContextND_Relation.
+ Coercion pl_cnd : ProgrammingLanguage >-> ContextND.
End Programming_Language.
-Implicit Arguments ND [ Judgment ].