This puzzle is dedicated to the memory of my colleague, Prof. David Kraines (1941-2026), who passed away last month. In addition to his decades of contributions to the Duke math department (he continued to organize our Putnam team and our summer undergrad research programs long after he was retired), David was also an avid crossword fan, and I always enjoyed sharing my new puzzles with him. He once constructed a cryptic in which every single entry was math-based! This puzzle doesn't quite get to that level, but (spoiler alert / trigger warning) there may be just a bit of math.
