[twoodfin]

Sure, no argument that s-expressions are wonderfully simple & expressive.

But most human languages—or at least the dominant ones that compose the vast bulk of the LLM training set—use more complex structuring rules for whatever evolutionary linguistic reasons. Easier error correction? Auditory disambiguation?

You could tell similar “just so” stories about computer language syntax, & why s-expressions didn’t win out over (say) XML-style tagging. And it turns out pseudo-XML is a great way to talk to LLMs.

EDIT: To be clear, by “s-expressions” I mean their typical use in Lisp programming of a function expression followed by a series of parameter expressions. The “grammar” is just eval/apply.