proposition: Lemma infimum_unique X r: order r -> uniqueness (greatest_lower_bound r X).
proof: Proof. rewrite /greatest_lower_bound => or. exact: (unique_greatest (proj1 (iorder_osr or (Zo_S (p:=lower_bound r X))))). Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)