Four-Color Reducibility of Planar Graphs Containing Subgraphs with Four-Point Boundaries.

Four-Color Reducibility of Planar Graphs Containing Subgraphs with Four-Point Boundaries.

Regular price $20.00 $16.00 Sale

It is known that a planar graph containing a proper subgraph with only three points in the boundary between the subgraph and its complement is four-color reducible; that is, if the subgraph and the complement plus the boundary are each colorable with...