> I'm writing a script that shows a person a math expression (like "2 + 3")
> waits for an answer, then returns if its right or wrong.
> What I want though, is for it to wait something like 3 seconds and, if
> there is no input, assume the user doesn't know and return "WRONG".
The easiest is if you just wait for the next key stroke:
this returns the key if one was pressed, otherwise NIL.
To wait for a full line of input, you could use 'abort':
(abort 3 (line T))
This also returns the line, or NIL if timed out.