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

[komame]

When using a variable in a CAS call on the PPL side, you should indicate that it contains an expression rather than a string.

Use expr like this:

Code:

    expression:="2^3";
    d:=CAS(expr(expression));

However, this still won't work in your case because PPL program cannot return symbolic results (Home doesn't work with symbols).

Programs that operate on symbolic expressions should be written in CAS, not PPL.