proposition: Lemma sqr_i : 'i%C ^+ 2 = -1 :> R[i].
proof: Proof. by rewrite exprS; simpc; rewrite complexr0 rmorphN. Qed.
imports: HB(structures) mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq choice fintype) mathcomp(bigop order ssralg ssrint div ssrnum rat poly closed_field) mathcomp(polyrcf matrix mxalgebra tuple mxpoly zmodp binomial realalg) mathcomp(mxpoly)