include "ground_2/notation/functions/identity_0.ma".
include "ground_2/notation/relations/isidentity_1.ma".
-include "ground_2/relocation/nstream_lift.ma".
include "ground_2/relocation/nstream_after.ma".
(* RELOCATION N-STREAM ******************************************************)
-let corec id: nstream ≝ ↑id.
+let corec id: rtmap ≝ ↑id.
interpretation "identity (nstream)"
'Identity = (id).
-definition isid: predicate nstream ≝ λt. t ≐ 𝐈𝐝.
+definition isid: predicate rtmap ≝ λf. f ≐ 𝐈𝐝.
interpretation "test for identity (trace)"
- 'IsIdentity t = (isid t).
+ 'IsIdentity f = (isid f).
(* Basic properties on id ***************************************************)
(* Basic properties on isid *************************************************)
+lemma isid_eq_repl_back: eq_stream_repl_back … isid.
+/2 width=3 by eq_stream_canc_sn/ qed-.
+
+lemma isid_eq_repl_fwd: eq_stream_repl_fwd … isid.
+/3 width=3 by isid_eq_repl_back, eq_stream_repl_sym/ qed-.
+
lemma isid_id: 𝐈⦃𝐈𝐝⦄.
// qed.
-lemma isid_push: ∀t. 𝐈⦃t⦄ → 𝐈⦃↑t⦄.
-#t #H normalize >id_unfold /2 width=1 by eq_seq/
+lemma isid_push: ∀f. 𝐈⦃f⦄ → 𝐈⦃↑f⦄.
+#f #H normalize >id_unfold /2 width=1 by eq_seq/
qed.
(* Basic inversion lemmas on isid *******************************************)
-lemma isid_inv_seq: ∀t,a. 𝐈⦃a@t⦄ → 𝐈⦃t⦄ ∧ a = 0.
-#t #a normalize >id_unfold in ⊢ (???%→?);
+lemma isid_inv_seq: ∀f,n. 𝐈⦃n@f⦄ → 𝐈⦃f⦄ ∧ n = 0.
+#f #n normalize >id_unfold in ⊢ (???%→?);
#H elim (eq_stream_inv_seq ????? H) -H /2 width=1 by conj/
qed-.
-lemma isid_inv_push: ∀t. 𝐈⦃↑t⦄ → 𝐈⦃t⦄.
-* #a #t #H elim (isid_inv_seq … H) -H //
+lemma isid_inv_push: ∀f. 𝐈⦃↑f⦄ → 𝐈⦃f⦄.
+* #n #f #H elim (isid_inv_seq … H) -H //
qed-.
-lemma isid_inv_next: ∀t. 𝐈⦃⫯t⦄ → ⊥.
-* #a #t #H elim (isid_inv_seq … H) -H
+lemma isid_inv_next: ∀f. 𝐈⦃⫯f⦄ → ⊥.
+* #n #f #H elim (isid_inv_seq … H) -H
#_ #H destruct
qed-.
+lemma isid_inv_gen: ∀f. 𝐈⦃f⦄ → ∃∃g. 𝐈⦃g⦄ & f = ↑g.
+* #n #f #H elim (isid_inv_seq … H) -H
+#Hf #H destruct /2 width=3 by ex2_intro/
+qed-.
+
+lemma isid_inv_eq_repl: ∀f1,f2. 𝐈⦃f1⦄ → 𝐈⦃f2⦄ → f1 ≐ f2.
+/2 width=3 by eq_stream_canc_dx/ qed-.
+
(* inversion lemmas on at ***************************************************)
-let corec id_inv_at: ∀t. (∀i. @⦃i, t⦄ ≡ i) → t ≐ 𝐈𝐝 ≝ ?.
-* #a #t #Ht lapply (Ht 0)
+let corec id_inv_at: ∀f. (∀i. @⦃i, f⦄ ≡ i) → f ≐ 𝐈𝐝 ≝ ?.
+* #n #f #Ht lapply (Ht 0)
#H lapply (at_inv_O1 … H) -H
#H0 >id_unfold @eq_seq
-[ cases H0 -a //
+[ cases H0 -n //
| @id_inv_at -id_inv_at
- #i lapply (Ht (⫯i)) -Ht cases H0 -a
+ #i lapply (Ht (⫯i)) -Ht cases H0 -n
#H elim (at_inv_SOx … H) -H //
]
qed-.
-lemma isid_inv_at: ∀i,t. 𝐈⦃t⦄ → @⦃i, t⦄ ≡ i.
+lemma isid_inv_at: ∀i,f. 𝐈⦃f⦄ → @⦃i, f⦄ ≡ i.
#i elim i -i
-[ * #a #t #H elim (isid_inv_seq … H) -H //
-| #i #IH * #a #t #H elim (isid_inv_seq … H) -H
+[ * #n #f #H elim (isid_inv_seq … H) -H //
+| #i #IH * #n #f #H elim (isid_inv_seq … H) -H
/3 width=1 by at_S1/
]
qed-.
-lemma isid_inv_at_mono: ∀t,i1,i2. 𝐈⦃t⦄ → @⦃i1, t⦄ ≡ i2 → i1 = i2.
+lemma isid_inv_at_mono: ∀f,i1,i2. 𝐈⦃f⦄ → @⦃i1, f⦄ ≡ i2 → i1 = i2.
/3 width=6 by isid_inv_at, at_mono/ qed-.
(* Properties on at *********************************************************)
lemma id_at: ∀i. @⦃i, 𝐈𝐝⦄ ≡ i.
/2 width=1 by isid_inv_at/ qed.
-lemma isid_at: ∀t. (∀i. @⦃i, t⦄ ≡ i) → 𝐈⦃t⦄.
+lemma isid_at: ∀f. (∀i. @⦃i, f⦄ ≡ i) → 𝐈⦃f⦄.
/2 width=1 by id_inv_at/ qed.
-lemma isid_at_total: ∀t. (∀i1,i2. @⦃i1, t⦄ ≡ i2 → i1 = i2) → 𝐈⦃t⦄.
-#t #Ht @isid_at
-#i lapply (at_total i t)
+lemma isid_at_total: ∀f. (∀i1,i2. @⦃i1, f⦄ ≡ i2 → i1 = i2) → 𝐈⦃f⦄.
+#f #Ht @isid_at
+#i lapply (at_total i f)
#H >(Ht … H) in ⊢ (???%); -Ht //
qed.
(* Properties on after ******************************************************)
-lemma after_isid_dx: ∀t2,t1,t. t2 ⊚ t1 ≡ t → t2 ≐ t → 𝐈⦃t1⦄.
-#t2 #t1 #t #Ht #H2 @isid_at_total
-#i1 #i2 #Hi12 elim (after_at1_fwd … Hi12 … Ht) -t1
+lemma after_isid_dx: ∀f2,f1,f. f2 ⊚ f1 ≡ f → f2 ≐ f → 𝐈⦃f1⦄.
+#f2 #f1 #f #Ht #H2 @isid_at_total
+#i1 #i2 #Hi12 elim (after_at1_fwd … Hi12 … Ht) -f1
/3 width=6 by at_inj, eq_stream_sym/
qed.
-lemma after_isid_sn: ∀t2,t1,t. t2 ⊚ t1 ≡ t → t1 ≐ t → 𝐈⦃t2⦄.
-#t2 #t1 #t #Ht #H1 @isid_at_total
-#i2 #i #Hi2 lapply (at_total i2 t1)
+lemma after_isid_sn: ∀f2,f1,f. f2 ⊚ f1 ≡ f → f1 ≐ f → 𝐈⦃f2⦄.
+#f2 #f1 #f #Ht #H1 @isid_at_total
+#i2 #i #Hi2 lapply (at_total i2 f1)
#H0 lapply (at_increasing … H0)
-#Ht1 lapply (after_fwd_at2 … (t1@❴i2❵) … H0 … Ht)
-/3 width=7 by at_repl_back, at_mono, at_id_le/
+#Ht1 lapply (after_fwd_at2 … (f1@❴i2❵) … H0 … Ht)
+/3 width=7 by at_eq_repl_back, at_mono, at_id_le/
qed.
(* Inversion lemmas on after ************************************************)
-let corec isid_after_sn: ∀t1,t2. 𝐈⦃t1⦄ → t1 ⊚ t2 ≡ t2 ≝ ?.
-* #a1 #t1 * * [ | #a2 ] #t2 #H cases (isid_inv_seq … H) -H
-#Ht1 #H1
-[ @(after_zero … H1) -H1 /2 width=1 by/
-| @(after_skip … H1) -H1 /2 width=5 by/
-]
+let corec isid_after_sn: ∀f1,f2. 𝐈⦃f1⦄ → f1 ⊚ f2 ≡ f2 ≝ ?.
+* #n1 #f1 * * [ | #n2 ] #f2 #H cases (isid_inv_seq … H) -H
+/3 width=7 by after_push, after_refl/
qed-.
-let corec isid_after_dx: ∀t2,t1. 𝐈⦃t2⦄ → t1 ⊚ t2 ≡ t1 ≝ ?.
-* #a2 #t2 * *
-[ #t1 #H cases (isid_inv_seq … H) -H
- #Ht2 #H2 @(after_zero … H2) -H2 /2 width=1 by/
-| #a1 #t1 #H @(after_drop … a1 a1) /2 width=5 by/
+let corec isid_after_dx: ∀f2,f1. 𝐈⦃f2⦄ → f1 ⊚ f2 ≡ f1 ≝ ?.
+* #n2 #f2 * *
+[ #f1 #H cases (isid_inv_seq … H) -H
+ /3 width=7 by after_refl/
+| #n1 #f1 #H @after_next [4,5: // |1,2: skip ] /2 width=1 by/
]
qed-.
-lemma after_isid_inv_sn: ∀t1,t2,t. t1 ⊚ t2 ≡ t → 𝐈⦃t1⦄ → t2 ≐ t.
-/3 width=4 by isid_after_sn, after_mono/
+lemma after_isid_inv_sn: ∀f1,f2,f. f1 ⊚ f2 ≡ f → 𝐈⦃f1⦄ → f2 ≐ f.
+/3 width=8 by isid_after_sn, after_mono/
qed-.
-lemma after_isid_inv_dx: ∀t1,t2,t. t1 ⊚ t2 ≡ t → 𝐈⦃t2⦄ → t1 ≐ t.
-/3 width=4 by isid_after_dx, after_mono/
+lemma after_isid_inv_dx: ∀f1,f2,f. f1 ⊚ f2 ≡ f → 𝐈⦃f2⦄ → f1 ≐ f.
+/3 width=8 by isid_after_dx, after_mono/
qed-.
(*
-lemma after_inv_isid3: ∀t1,t2,t. t1 ⊚ t2 ≡ t → 𝐈⦃t⦄ → 𝐈⦃t1⦄ ∧ 𝐈⦃t2⦄.
+lemma after_inv_isid3: ∀f1,f2,f. f1 ⊚ f2 ≡ f → 𝐈⦃t⦄ → 𝐈⦃t1⦄ ∧ 𝐈⦃t2⦄.
qed-.
*)