proposition: Lemma RinvE x : x != 0 -> Rinv x = x^-1.
proof: Proof. by move=> x_neq0; rewrite -[RHS]/(if _ then _ else _) x_neq0. Qed.
imports: Rdefinitions Raxioms RIneq Rbasic_fun Zwf Epsilon FunctionalExtensionality Ranalysis1 Rsqrt_def Rtrigo1 Reals mathcomp(all_ssreflect ssralg poly mxpoly ssrnum) HB(structures) mathcomp(boolp classical_sets) reals