fact: Definition hd_red_Mod_SCC'_union := fold_right (@union (term Sig)) empty sorted_hd_red_Mod_SCC'.
imports: Coq(Permutation Multiset Setoid PermutSetoid) CoLoR(SCCTopoOrdering AGraph ATrs RelUtil RelSub BoundNat AdjMat LogicUtil NatUtil SCC SCC_dec ListExtras SN VecUtil GDomainBij OptUtil Union SortUtil ListNodup ListPermutation)