New user frustration

[goetz]

I am using the Android Pro version, not a physical calculator. Unfortunately, the "firmware" is a bit older on that version (see some other discussion on this forum), and the software version does not give a clear indication, as it seems it was updated without using a newer source to build. It is version 14591, but no new features like Python. I tried my command also on the virtual calculator on Windows 10 (version 14592), and it worked.

What you may want to try: Go to the "Mem" menu (by hitting shift-mem (key)), then scroll down to Backups, to create a new backup. Then reset the calculator and see if the command works then. You should be able to restore the calcuator from the backup in the same menu later on, but I cannot guarantee, as i have never tried on a physical Prime (but it worked on the apps).

I found part of my solution in the built-in help. Just enter the "diff" command on the HP Prime command line, then hit the HELP key to see the help for diff. It shows some examples (see the example soft key!), including some with curly braces for multiple variables, and a 3rd parameter for the order. I guessed that adding a list with two numbers for both x and y would work, and it did. I found that the built-in help often helps and the examples will give an idea for some additional variants of commands. Not everything is documented, though.

The curly braces key you used (Shift-8) is the correct one, it inserts a pair of them.