09.06.2020, 16:44
If by "working" you mean "solving", and you don't care about proving that there's only one solution, then R1C6 must be "c" (and it follows that R2C6 is not "c").
If by "working" you mean "constructing", then you'll need something else (e.g. a variant rule) to resolve these cells, or else the puzzle has multiple solutions.
If by "working" you mean "constructing", then you'll need something else (e.g. a variant rule) to resolve these cells, or else the puzzle has multiple solutions.