fact: Definition wider_reality xr yr := match xr, yr with | Arbitrary, _ => true | Real xr, Real yr => wider_real xr yr | Real _, Arbitrary => false end.
imports: HB(structures) Coq(ssreflect ssrfun ssrbool) mathcomp(ssrnat eqtype choice order ssralg ssrnum ssrint) mathcomp(mathcomp_extra)