: A (g, f )-factor of a graph is a subset F of E such that for all v V, g(v) degF(v) f(v). Lovasz gave a necessary and sufficient condition for the existence of a (g, f )-factor...
Polygon spaces like Mℓ = {(u1, · · · , un) ∈ S1 × · · · S1 ; n i=1 liui = 0}/SO(2) or they three dimensional analogues Nℓ play an important rle in geometry and topolo...