(**************************************************************************)
include "basics/star.ma".
-include "basics/lists/list.ma".
+include "basics/lists/lstar.ma".
include "arithmetics/exp.ma".
include "xoa_notation.ma".
non associative with precedence 90
for @{'false}.
-lemma ex2_1_commute: ∀A0. ∀P0,P1:A0→Prop. (∃∃x0. P0 x0 & P1 x0) → ∃∃x0. P1 x0 & P0 x0.
-#A0 #P0 #P1 * /2 width=3/
-qed.
-
-(* relations *)
-
-definition confluent1: ∀A. relation A → predicate A ≝ λA,R,a0.
- ∀a1. R a0 a1 → ∀a2. R a0 a2 →
- ∃∃a. R a1 a & R a2 a.
-
-(* Note: confluent1 would be redundant if \Pi-reduction where enabled *)
-definition confluent: ∀A. predicate (relation A) ≝ λA,R.
- ∀a0. confluent1 … R a0.
-
(* arithmetics *)
lemma lt_refl_false: ∀n. n < n → ⊥.
notation > "◊"
non associative with precedence 90
for @{'nil}.
+
+definition map_cons: ∀A. A → list (list A) → list (list A) ≝ λA,a.
+ map … (cons … a).
+
+interpretation "map_cons" 'ho_cons a l = (map_cons ? a l).
+
+notation "hvbox(a ::: break l)"
+ right associative with precedence 47
+ for @{'ho_cons $a $l}.
+
+(* lstar *)
+
+(* Note: this cannot be in lib because of the missing xoa quantifier *)
+lemma lstar_inv_pos: ∀A,B,R,l,b1,b2. lstar A B R l b1 b2 → 0 < |l| →
+ ∃∃a,ll,b. a::ll = l & R a b1 b & lstar A B R ll b b2.
+#A #B #R #l #b1 #b2 #H @(lstar_ind_l ????????? H) -b1
+[ #H elim (lt_refl_false … H)
+| #a #ll #b1 #b #Hb1 #Hb2 #_ #_ /2 width=6/ (**) (* auto fail if we do not remove the inductive premise *)
+]
+qed-.