fact: Definition Qpos_sub (a b : Q) : a < b -> {c : Qpos | b == a + proj1_sig c}.
imports: Coq.Logic.Eqdep_dec Coq.QArith.QArith Coq.QArith.Qabs Coq.QArith.Qpower Coq.QArith.Qround CoRN.model.totalorder.QMinMax CoRN.order.TotalOrder