Testing xCAS version 1.2.3-9 (2017)

[DrD]

I wonder why I don't seem to get that. I have tried both upper and lower case expr().
(Lower case expr() gets changed to upper case EXPR() in the CAS history).

*[Weird (update)]*
I just used [shift] [esc] to clear the CAS history, and now, I'm also getting:

solve(subst(expr(a),x = 60),y) ==> {-110} on the emulator.

Prior to that, for the several times I tried it, the response was [[]]. I wonder what that was all about? (Why or did) clearing the history have anything to do with it?

Yesterday, I was doing a lot of work with various commands, and the prime began returning error messages for things I know worked earlier. I finally thought to do a calculator 'reset', and everything since then began working properly, once again. Today, I was using the above example, many times, and only getting the empty matrix back. The same entry on the physical prime consistently returned {-110}.

Incidentally, a companion problem ALWAYS worked on the emulator before and after clearing the CAS history:

solve(subst(expr(a),y = 23),x) ==> {-13/2}

I'm wondering now, if the x or y variables may have had some previous content (before I cleared the CAS history), and my example might have failed due to that.

It's probably just a problem related to the emulator on my end. I'm sorry about that.