Earlier today I set you three examples of a word puzzle that illuminates one of the smash hits of theoretical computer science. (To read about this result, the PCP theorem, please check out the original post.)

In the puzzle, crossword-style clues each point to a vertical column. The answer to each clue is a three-letter word, made up from the three letters that the clue points to.

The point about these puzzles is that you can solve them fully, or partially. (As explained in the original post.) Below are the puzzles, and full solutions.