proposition: Lemma section_repr_isog s1 s2 : s1 \isog s2 -> section_repr s1 = section_repr s2.
proof: Proof. by move=> iso12; congr (odflt _ _); apply: eq_pick => s; apply: isog_transr. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype bigop finset fingroup morphism) mathcomp(automorphism quotient action gseries)