proposition: Lemma epsilon_inh_irrelevance : forall (A:Type) (i j : inhabited A) (P:A->Prop), (exists x, P x) -> epsilon i P = epsilon j P.
proof: Proof. intros. unfold epsilon, classical_indefinite_description. destruct (excluded_middle_informative (exists x : A, P x)) as [|[]]; trivial. Qed.
imports: Classical ChoiceFacts