Add pi and sig subtyping semantic rules

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Yiyun Liu 2025-02-08 22:15:04 -05:00
parent 916e0bcd75
commit 02e6c9e025

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@ -512,8 +512,6 @@ Qed.
Definition ρ_ok {n} (Γ : fin n -> PTm n) (ρ : fin n -> PTm 0) := forall i k PA,
subst_PTm ρ (Γ i) k PA -> PA (ρ i).
Definition Γ_eq {n} (Γ Δ : fin n -> PTm n) := forall i, DJoin.R (Γ i) (Δ i).
Definition SemWt {n} Γ (a A : PTm n) := forall ρ, ρ_ok Γ ρ -> exists k PA, subst_PTm ρ A k PA /\ PA (subst_PTm ρ a).
Notation "Γ ⊨ a ∈ A" := (SemWt Γ a A) (at level 70).
@ -908,24 +906,7 @@ Proof.
hauto l:on use:DJoin.transitive.
Qed.
Lemma SLEq_Eq n Γ (A B : PTm n) i :
Γ A B PUniv i ->
Γ A B.
Proof. move /SemEq_SemWt => h.
qauto l:on use:SemWt_SemLEq, Sub.FromJoin.
Qed.
Lemma SLEq_Transitive n Γ (A B C : PTm n) :
Γ A B ->
Γ B C ->
Γ A C.
Proof.
move => ha hb.
apply SemLEq_SemWt in ha, hb.
have ? : SN B by hauto l:on use:SemWt_SN.
move : ha => [ha0 [i [ha1 ha2]]]. move : hb => [hb0 [j [hb1 hb2]]].
qauto l:on use:SemWt_SemLEq, Sub.transitive.
Qed.
Definition Γ_eq {n} (Γ Δ : fin n -> PTm n) := forall i, DJoin.R (Γ i) (Δ i).
Lemma Γ_eq_ρ_ok n Γ Δ (ρ : fin n -> PTm 0) : Γ_eq Γ Δ -> Γ -> ρ_ok Γ ρ -> ρ_ok Δ ρ.
Proof.
@ -942,6 +923,44 @@ Proof.
hauto l:on use: DJoin.substing.
Qed.
Definition Γ_sub {n} (Γ Δ : fin n -> PTm n) := forall i, Sub.R (Γ i) (Δ i).
Lemma Γ_sub_ρ_ok n Γ Δ (ρ : fin n -> PTm 0) : Γ_sub Γ Δ -> Γ -> ρ_ok Γ ρ -> ρ_ok Δ ρ.
Proof.
move => hΓΔ h.
move => i k PA hPA.
move : . rewrite /SemWff. move /(_ i) => [j].
move => .
rewrite SemWt_Univ in .
have {}/ := h.
move => [S hS].
move /(_ i) in h. suff : forall x, S x -> PA x by qauto l:on.
move : InterpUniv_Sub hS hPA. repeat move/[apply].
apply. by apply Sub.substing.
Qed.
Lemma Γ_sub_refl n (Γ : fin n -> PTm n) :
Γ_sub Γ Γ.
Proof. sfirstorder use:Sub.refl. Qed.
Lemma Γ_sub_cons n (Γ Δ : fin n -> PTm n) A B :
Sub.R A B ->
Γ_sub Γ Δ ->
Γ_sub (funcomp (ren_PTm shift) (scons A Γ)) (funcomp (ren_PTm shift) (scons B Δ)).
Proof.
move => h h0.
move => i.
destruct i as [i|].
rewrite /funcomp. substify. apply Sub.substing. by asimpl.
rewrite /funcomp.
asimpl. substify. apply Sub.substing. by asimpl.
Qed.
Lemma Γ_sub_cons' n (Γ : fin n -> PTm n) A B :
Sub.R A B ->
Γ_sub (funcomp (ren_PTm shift) (scons A Γ)) (funcomp (ren_PTm shift) (scons B Γ)).
Proof. eauto using Γ_sub_refl ,Γ_sub_cons. Qed.
Lemma Γ_eq_refl n (Γ : fin n -> PTm n) :
Γ_eq Γ Γ.
Proof. sfirstorder use:DJoin.refl. Qed.
@ -958,7 +977,6 @@ Proof.
rewrite /funcomp.
asimpl. substify. apply DJoin.substing. by asimpl.
Qed.
Lemma Γ_eq_cons' n (Γ : fin n -> PTm n) A B :
DJoin.R A B ->
Γ_eq (funcomp (ren_PTm shift) (scons A Γ)) (funcomp (ren_PTm shift) (scons B Γ)).
@ -1082,13 +1100,102 @@ Lemma SBind_inv1 n Γ i p (A : PTm n) B :
hauto lq:on rew:off use:InterpUniv_Bind_inv.
Qed.
Lemma SE_Bind_Proj1 n Γ p (A0 A1 : PTm n) B0 B1 i :
Γ PBind p A0 B0 PBind p A1 B1 PUniv i ->
Γ A0 A1 PUniv i.
Lemma SSu_Eq n Γ (A B : PTm n) i :
Γ A B PUniv i ->
Γ A B.
Proof. move /SemEq_SemWt => h.
qauto l:on use:SemWt_SemLEq, Sub.FromJoin.
Qed.
Lemma SSu_Transitive n Γ (A B C : PTm n) :
Γ A B ->
Γ B C ->
Γ A C.
Proof.
move /SemEq_SemWt => [h0][h1]he.
apply SemWt_SemEq; eauto using SBind_inv1.
move /DJoin.bind_inj : he. tauto.
move => ha hb.
apply SemLEq_SemWt in ha, hb.
have ? : SN B by hauto l:on use:SemWt_SN.
move : ha => [ha0 [i [ha1 ha2]]]. move : hb => [hb0 [j [hb1 hb2]]].
qauto l:on use:SemWt_SemLEq, Sub.transitive.
Qed.
Lemma ST_Univ n Γ i j :
i < j ->
Γ PUniv i : PTm n PUniv j.
Proof.
move => ?.
apply SemWt_Univ. move => ρ hρ. eexists. by apply InterpUniv_Univ.
Qed.
Lemma SSu_Univ n Γ i j :
i <= j ->
Γ PUniv i : PTm n PUniv j.
Proof.
move => h. apply : SemWt_SemLEq; eauto using ST_Univ.
sauto lq:on.
Qed.
Lemma SSu_Pi n Γ (A0 A1 : PTm n) B0 B1 :
Γ ->
Γ A1 A0 ->
funcomp (ren_PTm shift) (scons A0 Γ) B0 B1 ->
Γ PBind PPi A0 B0 PBind PPi A1 B1.
Proof.
move => hA hB.
have ? : SN A0 /\ SN A1 /\ SN B0 /\ SN B1
by hauto l:on use:SemLEq_SN_Sub.
apply SemLEq_SemWt in hA, hB.
move : hA => [hA0][i][hA1]hA2.
move : hB => [hB0][j][hB1]hB2.
apply : SemWt_SemLEq; last by hauto l:on use:Sub.PiCong.
hauto l:on use:ST_Bind.
apply ST_Bind; eauto.
have hΓ' : funcomp (ren_PTm shift) (scons A1 Γ) by hauto l:on use:SemWff_cons.
move => ρ hρ.
suff : ρ_ok (funcomp (ren_PTm shift) (scons A0 Γ)) ρ by hauto l:on.
move : Γ_sub_ρ_ok hΓ' hρ; repeat move/[apply]. apply.
hauto lq:on use:Γ_sub_cons'.
Qed.
Lemma SSu_Sig n Γ (A0 A1 : PTm n) B0 B1 :
Γ ->
Γ A0 A1 ->
funcomp (ren_PTm shift) (scons A1 Γ) B0 B1 ->
Γ PBind PSig A0 B0 PBind PSig A1 B1.
Proof.
move => hA hB.
have ? : SN A0 /\ SN A1 /\ SN B0 /\ SN B1
by hauto l:on use:SemLEq_SN_Sub.
apply SemLEq_SemWt in hA, hB.
move : hA => [hA0][i][hA1]hA2.
move : hB => [hB0][j][hB1]hB2.
apply : SemWt_SemLEq; last by hauto l:on use:Sub.SigCong.
2 : { hauto l:on use:ST_Bind. }
apply ST_Bind; eauto.
have hΓ' : funcomp (ren_PTm shift) (scons A1 Γ) by hauto l:on use:SemWff_cons.
have hΓ'' : funcomp (ren_PTm shift) (scons A0 Γ) by hauto l:on use:SemWff_cons.
move => ρ hρ.
suff : ρ_ok (funcomp (ren_PTm shift) (scons A1 Γ)) ρ by hauto l:on.
apply : Γ_sub_ρ_ok; eauto.
hauto lq:on use:Γ_sub_cons'.
Qed.
Lemma SSu_Pi_Proj1 n Γ (A0 A1 : PTm n) B0 B1 :
Γ PBind PPi A0 B0 PBind PPi A1 B1 ->
Γ A1 A0.
Proof.
move /SemLEq_SemWt => [h0][h1][h2]he.
apply : SemWt_SemLEq; eauto using SBind_inv1.
hauto lq:on rew:off use:Sub.bind_inj.
Qed.
Lemma SSu_Sig_Proj1 n Γ (A0 A1 : PTm n) B0 B1 :
Γ PBind PSig A0 B0 PBind PSig A1 B1 ->
Γ A0 A1.
Proof.
move /SemLEq_SemWt => [h0][h1][h2]he.
apply : SemWt_SemLEq; eauto using SBind_inv1.
hauto lq:on rew:off use:Sub.bind_inj.
Qed.
Lemma SE_Bind_Proj2 n Γ p (a0 a1 A0 A1 : PTm n) B0 B1 i :
@ -1114,14 +1221,6 @@ Proof.
hauto lq:on ctrs:rtc inv:option.
Qed.
Lemma ST_Univ n Γ i j :
i < j ->
Γ PUniv i : PTm n PUniv j.
Proof.
move => ?.
apply SemWt_Univ. move => ρ hρ. eexists. by apply InterpUniv_Univ.
Qed.
#[export]Hint Resolve ST_Var ST_Bind ST_Abs ST_App ST_Pair ST_Proj1 ST_Proj2 ST_Univ ST_Conv
SE_Refl SE_Symmetric SE_Transitive SE_Bind SE_Abs SE_App SE_Proj1 SE_Proj2
SE_Conv SE_Bind_Proj1 SE_Bind_Proj2 SemWff_nil SemWff_cons : sem.