Maria Del Río-Francos: Notes of the dual and petrie operations on maps

Povzetek. Wilson and Lins showed that for a map M it can be seen that a bijection p and the duality d are operators on M that generate a subgroup of the symmetric group of the set of flags of M, isomorphic to S₃. In this talk I'll explain these operators, based on Wilson's paper: "Operators over regular maps".