Xcas provides you with a program editor, which you can open with
Alt+P. This can be useful for writing small programs, but
for writing larger programs you may want to use your usual editor.
(Note that this requires an editor, such as emacs, and not a
word processor.) If you use your own editor, then you will need to
save the program to a file, such as myprog.cxx, and then load
it into Xcas with the command line command load:
Input: