(*** at *)
inductive fr2_nat: fr2_map → relation nat ≝
(*** at_nil *)
-| fr2_nat_nil (l):
- fr2_nat (◊) l l
+| fr2_nat_empty (l):
+ fr2_nat (𝐞) l l
(*** at_lt *)
| fr2_nat_lt (f) (d) (h) (l1) (l2):
l1 < d → fr2_nat f l1 l2 → fr2_nat (❨d,h❩;f) l1 l2
(* Basic inversions *********************************************************)
(*** at_inv_nil *)
-lemma fr2_nat_inv_nil (l1) (l2):
- @❨l1, ◊❩ ≘ l2 → l1 = l2.
-#l1 #l2 @(insert_eq_1 … (◊))
+lemma fr2_nat_inv_empty (l1) (l2):
+ @❨l1, 𝐞❩ ≘ l2 → l1 = l2.
+#l1 #l2 @(insert_eq_1 … (𝐞))
#f * -f -l1 -l2
[ //
| #f #d #h #l1 #l2 #_ #_ #H destruct
qed-.
(*** at_inv_cons *)
-lemma fr2_nat_inv_cons (f) (d) (h) (l1) (l2):
+lemma fr2_nat_inv_lcons (f) (d) (h) (l1) (l2):
@❨l1, ❨d,h❩;f❩ ≘ l2 →
∨∨ ∧∧ l1 < d & @❨l1, f❩ ≘ l2
| ∧∧ d ≤ l1 & @❨l1+h, f❩ ≘ l2.
qed-.
(*** at_inv_cons *)
-lemma fr2_nat_inv_cons_lt (f) (d) (h) (l1) (l2):
+lemma fr2_nat_inv_lcons_lt (f) (d) (h) (l1) (l2):
@❨l1, ❨d,h❩;f❩ ≘ l2 → l1 < d → @❨l1, f❩ ≘ l2.
#f #d #h #l1 #h2 #H
-elim (fr2_nat_inv_cons … H) -H * // #Hdl1 #_ #Hl1d
+elim (fr2_nat_inv_lcons … H) -H * // #Hdl1 #_ #Hl1d
elim (nlt_ge_false … Hl1d Hdl1)
qed-.
(*** at_inv_cons *)
-lemma fr2_nat_inv_cons_ge (f) (d) (h) (l1) (l2):
+lemma fr2_nat_inv_lcons_ge (f) (d) (h) (l1) (l2):
@❨l1, ❨d,h❩;f❩ ≘ l2 → d ≤ l1 → @❨l1+h, f❩ ≘ l2.
#f #d #h #l1 #h2 #H
-elim (fr2_nat_inv_cons … H) -H * // #Hl1d #_ #Hdl1
+elim (fr2_nat_inv_lcons … H) -H * // #Hl1d #_ #Hdl1
elim (nlt_ge_false … Hl1d Hdl1)
qed-.