I almost can't believe I did it. I guess I thought it would be harder
or more involved. Maybe divmod will be a pill?
Kinda relaxing after wasting the weekend nerd-sniped by curses.
but it breaks associativity or is it commutivity?
Anyway you can't add THREE or more things in one expression (yet)
because adding OberonInt objects returns a two-tuple.
I could adjust the semantics of ObInt to accept such two-tuples and do
add_with_carry() but that's probably more trouble than it's worth.
Just gotta be careful with math expressions, eh?