Through deduction, I've created a matrix of points that only have two
possibilities (most have more).
So I'm cycling through the "two" matrix in successive levels of complexity.
I mean try the first (2 cases), then the 1st and 2nd (4 cases), then the
1st and 2nd and 3rd (8 cases), etc.
I agree about loops and/or recursion - but couldn't come up with an
algorithm.