proposition: Lemma itv_intro {x} : x%:inum = x%:inum :> R.
proof: Proof. by []. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool) mathcomp(ssrnat eqtype choice order ssralg ssrnum ssrint) mathcomp(interval) mathcomp(mathcomp_extra boolp) signed