proposition: Lemma oprob_divRposxxy' (x y : Rpos) : (0 < x / (x + y) < 1)%O.
proof: Proof. have [/RltP ? /RltP ?] := oprob_divRposxxy x y. exact/andP. Qed.
imports: mathcomp(all_ssreflect) mathcomp(all_algebra vector reals normedtype) mathcomp(mathcomp_extra boolp) mathcomp(Rstruct) ssrR realType_ext Reals Lra mathcomp(lra)