Thank you! I'll watch it in full tonight. I'm not sure if you mention it or not, but are you using a special APL keyboard? Curious how you enter the characters.
The Emacs mode provides two different methods to input APL symbols. It allows you to set a prefix key (like Super for example) that will map to the symbols, or you can use the APL imput method which uses "." (period) as a prefix when typing them.
When using it, you can type C-c C-k which will open a quick help that shows they keymap.
