@christianp If you render a preview on the fly, I would expect it to be clear. Especially if the student can see the `x*y` syntax somewhere (help text etc.). I would consider `p*i` about as logical interpretation as `s*i*n`.
@christianp That’s an excellent counterexample. I agree that `x*i` could reasonably come up. A few years ago, I wouldn’t even have associated the word ”xi” with the letter ξ (the Finnish transliteration being ”ksii”).
@petrilaarne what about the letter ξ, transliterated as 'xi'? I reckon `x*i` is the most common interpretation of that.
The system already renders a preview of the interpreted expression on the fly, but students either ignore it or misinterpret it - if they're not expecting a multiplication symbol, they don't notice it's missing.