fact: Definition BRinv x (aux:= fun z => BQps -s fun_image z BQinv) := Yo (rationalp x) (BR_of_Q (BQinv (BQ_of_R x))) (Yo (inc x BRps) (aux x) (BRopp (aux (BRopp x)))).
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)