ST Code Breaker Puzzle in Prolog

Since it was a pretty easy puzzle this week, I thought I'd have a go a cracking the Sunday Telegraph "Code Breaker" using Prolog. Prolog is kind of a unique language, one which I studied in the AI labs at Edinburgh about 30 years ago, but on today's evidence, barely know! But we got there. Fairly self-explanatory if you have the puzzle in front of you. This was the puzzle for the 13th April, 2025. As I say, most weeks it's a fair bit harder, so I'll tackle a couple more in due course. And I clarify: I only ever bought the grim Sunday Telegraph for the puzzles. Oh, and its broadsheet size makes it ideal for putting under the cat's litter tray.