fact: Definition normedTI A G L := [&& A != set0, trivIset (A :^: G) & 'N_G(A) == L].
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div) mathcomp(fintype bigop prime finset fingroup morphism) mathcomp(perm action quotient gproduct cyclic center) mathcomp(pgroup nilpotent sylow hall abelian)