proposition: Lemma intrEfloor x : x \is a int_num = ((floor x)%:~R == x).
proof: Proof. by apply/intrP/eqP => [[n ->] | <-]; [rewrite intrKfloor | exists (floor x)]. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order ssralg poly ssrnum ssrint)