proposition: Lemma intrEceil x : x \is a int_num = ((ceil x)%:~R == x).
proof: Proof. by rewrite mulrNz eqr_oppLR -intrEfloor !intrE opprK orbC. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order ssralg poly ssrnum ssrint)