proposition: Lemma prob_divRposxxy' (x y : Rpos) : (0 <= x / (x + y) <= 1)%O.
proof: Proof. have [/RleP ? /RleP ?] := prob_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)