proposition: Lemma inter_irrefl_equiv A (r r' : relation A) : r ∩ r' ≡ ∅₂ <-> irreflexive (r' ⨾ r⁻¹).
proof: Proof. firstorder. Qed.
imports: Program.Basics Arith micromega.Lia Permutation List Setoid HahnBase HahnList HahnRelationsBasic HahnSets