eclipsegirl wrote:
When I went back to use the Clear and Erase buttons, they wouldn’t work
I'm thinking this is because those buttons are trying to be "smart",
and won't respond if there are no numbers in the puzzle.
Later the pencilled in numbers were added, and I didn't consider the case where
a puzzle has _only_ pencilled numbers
update: I simplified things by now always allowing those two buttons to operate.
(and the condition was "even smarter": the buttons would not respond if there was no undo history)