proposition: Theorem sort_eq_2 : forall (l:list A)(def:A)(t1 t2:bin), bin_A' l def (sort_bin t1) = bin_A' l def (sort_bin t2)-> bin_A' l def t1 = bin_A' l def t2.
proof: Proof. intros l def t1 t2. rewrite <- (sort_eq l def t1); rewrite <- (sort_eq l def t2). trivial. Qed.
imports: ZArith List Arith Lia Zwf Relations Inverse_Image Transitive_Closure Zdiv