QED: Generate and solve Latin Square arithmetic operations puzzles

An experiment that lets you waste time on KenKen-like puzzles, no longer present in the Times. This is what Igor is for, right? Please don't sue me if you waste too much of your time.

Lets you play with 4x4 up to 9x9 puzzles. A fairly simple user-interface, with a control panel to enter possible values, and hook functions to enter guesses. Comes with a bunch of puzzles!

No great code here, but it does enough to solve puzzles, which helps to avoid ambiguous puzzles without a unique solution.