proposition: Lemma quotient_sol G H : solvable G -> solvable (G / H).
proof: Proof. exact: morphim_sol. Qed.
imports: mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(fintype div bigop prime finset fingroup morphism) mathcomp(automorphism quotient commutator gproduct) mathcomp(gfunctor center gseries cyclic)