@kellysmith12.21 I like it. That’s how I’ve wanted to use infix ops personally. No mixing of different ops allowed unless it’s a small fixed group that the rules are clearly established for, and no extensibility in precedence rules. “Infix” shouldn’t mean “never use parentheses”.

I would probably be fine with even just Hackett’s system where you can’t mix different ops at all, but there are too many people too used to math notation for that. It would be an annoying surprise for lots of users that they can’t mix + and *.