This alternative formulation makes the equivalence of the Woodward–Hoffmann rules to the Dewar–Zimmerman analysis (see below) clear. An even total number of phase inversions is equivalent to an even number of antarafacial components and corresponds to Hückel topology, requiring 4"n" + 2 electrons for aromaticity, while an odd total number of phase inversions is equivalent to an odd number of antarafacial components and corresponds to Möbius topology, requiring 4"n" electrons for aromaticity. To summarize aromatic transition state theory: "Thermal pericyclic" "reactions proceed via" (4"n" + 2)"-electron Hückel or" (4"n")"-electron Möbius transition states".