The question is, will it take the crown for "best book about combinator calculi" from To Mock a Mockingbird? At least, Raymond Smullyan's writing style is much

The question is, will it take the crown for "best book about combinator calculi" from To Mock a Mockingbird? At least, Raymond Smullyan's writing style is much more enjoyable than Wolfram's. As fun as the puzzles and whimsical framing are in the latter book, I have been looking for a more straightforward book to suggest to people learning about combinators. The table of contents is intriguing, but I doubt this will be the concise introduction I'm looking for.