In article <firstname.lastname@example.org>, Jonathan Welton wrote: > An actual proof must use the hex nature of the board or, alternatively, > that 3 cells meet at each vertex. A proof is given in
The key fact I need is that if a red path is blocked from going around blue hex A by blue hex B, then A and B are adjacent. That property does not hold on a checkerboard. Is this what you mean by using the hex nature of the board?