A subgroup HHH of the group GGG is normal if for any g∈Hg \in Hg∈H, the left and right cosets of HHH are equal. That is, if gH=HggH = HggH=Hg for all g∈Gg \in Gg∈G. This is denoted H◃GH\triangleleft GH◃G.
Wikidata ID: Q743179