[HP PPL] Concatenation inside CAS(..) command does not work

[komame]

I know that the result can be displayed, but that's just a side effect of the approach you used. The Home mode, even though it displays the result, doesn't actually understand it.

So, the question is, why do it in Home mode when doing it in CAS allows you not only to get the result but also to continue operating on it? For instance, you can substitute the result of one of your functions into another one of your functions (without using strings, just regular symbolic expressions as input).

The HP Prime is designed to do such things on the CAS side (CAS program with #CAS #END region).

Is there a particular reason why you need to do it in PPL (Home)?