proposition: Lemma s_of_0q q : [s_of 0%:pr, q] = q.
proof: Proof. by apply/val_inj; rewrite /= s_of_pqE onem0 mul1r onemK. Qed.
imports: mathcomp(all_ssreflect ssralg ssrnum) mathcomp(reals normedtype) mathcomp(mathcomp_extra boolp) mathcomp(lra ring Rstruct)