initial |  boundary | start/end |    assign | 
        0 |         1 |         1 |         1 | 
        1 |         1 |         1 |         1 | 
      000 |       000 |       000 |         1 | 
      101 |       101 |       101 |       101 | 
      010 |       010 |       010 |       010 | 
Argument "1 * 0 = 0" isn't numeric in numeric eq (==) at ./pm_example.pl line 16.
1 * 0 = 0 | 1 * 1 = 0 | 1 * 0 = 0 | 1 * 0 = 0 |