proposition: Lemma Rinvx_out : {in predC unit_R, Rinvx =1 id}.
proof: Proof. by move=> x; rewrite inE/= /Rinvx -if_neg => ->. Qed.
imports: Rdefinitions Raxioms RIneq Rbasic_fun Zwf Epsilon FunctionalExtensionality Ranalysis1 Rsqrt_def Rtrigo1 Reals mathcomp(all_ssreflect ssralg poly mxpoly ssrnum) HB(structures)