Any time you provide a printout of an assignment, also include a description of
it in English (or a diagram, or something).
If a question asks you to provide an assignment, you do not need to provide
_all_ assignments. One will do.
Yes, the extra credit is worth actual points. (Note that an "extra credit"
problem is distinct from a "bonus challenge!")
This is an individual assignment.
The axioms look quite a bit more readable when the .txt files are opened, than
they do when they are loaded into the proof checker. Keep this in mind when you
are building a strategy for solving a proof.
If you are saving/loading the proofs as you work on them, you should be sure to Output
Proof the proof as well as saving them. Output Proof will write
the proof in a human-readable format.