A graph
G has vertices 1, 2, ..., n, and its edges are a list of lists of length 2. The graphic arrangement
A(G) of
G is, by definition, the subarrangement of the type A_(n-1) arrangement with hyperplanes
x_i-x_j for each edge
{i,j} of
GG = {{1,2},{2,3},{3,4},{4,1}}; -- a four-cycle |
AG = graphic G |
describe AG |
rank AG -- the number of vertices minus number of components |
ring AG |
ring graphic(G,ZZ[x,y,z,w]) |