Usage of MID()

[matalog]

(04-16-2022 05:06 PM)StephenG1CMZ Wrote:  This will work in PPL:
ST:="123";
CAS("mid(ST, 6) ");
It also works from CAS home screen - I haven't tried it within a CAS program.

That is the second time this week I have seen a suggestion to use CAS( something) as a work around.

What does that use of CAS do, as it usually contains more quotations that you would usually see?

Is it documented in the manual?