arg() crashes the emulator

[Angus]

Thanks a lot!
Many functions are unknown, hidden or known but just overlooked. All have in common that they come to life by examples. If only I would not suffer from cas<->home paranoia... There is a good chance that I will come up with related problems and questions indicating that I did not fully get all points. :-(
I did not understand why you proposed your code at a first glance. After trying string() in cas mode I noticed that the brackets around (x^2) vanish...so everything makes sense. But not being intuitive I think. That prime is hard to assess....

edit:
...except that string() leads to STRING().
One more question. I've just looked at the help system about mid() command. There it is capitalized.... Is that of importance? You mentioned in an other thread that several commands are essentially the same but behave differently if there is a home<->cas issue with them and if they are written in capital letters or not. I think you mentioned case and return aswell. These are 3 commands with obviously slighty different behaviour. I did not find case and return in the help (case leads to help CASE), so could you point out what differs with them?

case/CASE
return/RETURN
mid/MID
(..)

You said these nuances are important to learn. Thank you


edit2:

In cas the instring() command gives 3. which is a real I think? mid() does not like 3.-2 as parameter. I cannot figure out what causes that. Any