sp-eta-postpone/theories/common.v
2025-02-21 14:35:34 -05:00

108 lines
2.8 KiB
Coq

Require Import Autosubst2.fintype Autosubst2.syntax ssreflect.
From Ltac2 Require Ltac2.
Import Ltac2.Notations.
Import Ltac2.Control.
From Hammer Require Import Tactics.
Definition renaming_ok {n m} (Γ : fin n -> PTm n) (Δ : fin m -> PTm m) (ξ : fin m -> fin n) :=
forall (i : fin m), ren_PTm ξ (Δ i) = Γ (ξ i).
Lemma up_injective n m (ξ : fin n -> fin m) :
(forall i j, ξ i = ξ j -> i = j) ->
forall i j, (upRen_PTm_PTm ξ) i = (upRen_PTm_PTm ξ) j -> i = j.
Proof.
sblast inv:option.
Qed.
Local Ltac2 rec solve_anti_ren () :=
let x := Fresh.in_goal (Option.get (Ident.of_string "x")) in
intro $x;
lazy_match! Constr.type (Control.hyp x) with
| fin _ -> _ _ => (ltac1:(case;hauto lq:on rew:off use:up_injective))
| _ => solve_anti_ren ()
end.
Local Ltac solve_anti_ren := ltac2:(Control.enter solve_anti_ren).
Lemma ren_injective n m (a b : PTm n) (ξ : fin n -> fin m) :
(forall i j, ξ i = ξ j -> i = j) ->
ren_PTm ξ a = ren_PTm ξ b ->
a = b.
Proof.
move : m ξ b. elim : n / a => //; try solve_anti_ren.
Qed.
Inductive HF : Set :=
| H_Pair | H_Abs | H_Univ | H_Bind (p : BTag) | H_Nat | H_Suc | H_Zero | H_Bot.
Definition ishf {n} (a : PTm n) :=
match a with
| PPair _ _ => true
| PAbs _ => true
| PUniv _ => true
| PBind _ _ _ => true
| PNat => true
| PSuc _ => true
| PZero => true
| _ => false
end.
Definition toHF {n} (a : PTm n) :=
match a with
| PPair _ _ => H_Pair
| PAbs _ => H_Abs
| PUniv _ => H_Univ
| PBind p _ _ => H_Bind p
| PNat => H_Nat
| PSuc _ => H_Suc
| PZero => H_Zero
| _ => H_Bot
end.
Fixpoint ishne {n} (a : PTm n) :=
match a with
| VarPTm _ => true
| PApp a _ => ishne a
| PProj _ a => ishne a
| PBot => true
| PInd _ n _ _ => ishne n
| _ => false
end.
Definition isbind {n} (a : PTm n) := if a is PBind _ _ _ then true else false.
Definition isuniv {n} (a : PTm n) := if a is PUniv _ then true else false.
Definition ispair {n} (a : PTm n) :=
match a with
| PPair _ _ => true
| _ => false
end.
Definition isnat {n} (a : PTm n) := if a is PNat then true else false.
Definition iszero {n} (a : PTm n) := if a is PZero then true else false.
Definition issuc {n} (a : PTm n) := if a is PSuc _ then true else false.
Definition isabs {n} (a : PTm n) :=
match a with
| PAbs _ => true
| _ => false
end.
Definition ishf_ren n m (a : PTm n) (ξ : fin n -> fin m) :
ishf (ren_PTm ξ a) = ishf a.
Proof. case : a => //=. Qed.
Definition isabs_ren n m (a : PTm n) (ξ : fin n -> fin m) :
isabs (ren_PTm ξ a) = isabs a.
Proof. case : a => //=. Qed.
Definition ispair_ren n m (a : PTm n) (ξ : fin n -> fin m) :
ispair (ren_PTm ξ a) = ispair a.
Proof. case : a => //=. Qed.
Definition ishne_ren n m (a : PTm n) (ξ : fin n -> fin m) :
ishne (ren_PTm ξ a) = ishne a.
Proof. move : m ξ. elim : n / a => //=. Qed.