(* =========================== MEREOLOGICAL THEOREMS ========================== *)

(* Theorems 26 and 27 show that in mereology, the class of a and the class of the class of a stand for the same object, which is in contrast with set theory *)
Lemma MereoT26 : forall A a, A ε Kl a ⊃ A ε Kl (Kl a).