proposition: Lemma invq_def x : invq x = fracq (invq_subdef (valq x)).
proof: Proof. by case: x. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order ssralg countalg div ssrnum) mathcomp(ssrint prime archimedean)