A student writes:

Dear Prof. Patt,

I had finished problem set 1 on Thursday, and have noticed that an
increasing number of problems from it are being postponed, or will 
appear modified later.  If I already completed problems 1-10 correctly,
should I turn them all in on Wednesday?  Should I make a copy, so 
that I won't have to re-do them when they are re-assigned?

Thank you,

<name withheld to protect one who doesn't want to do a problem twice>

Glad to see that you are ahead of where we are in class.
Great!  I hope you keep it up.

We will not grade the two problems that we postponed.  So, if you do not
want to redo them for the second problem set, then I guess you should copy
and save them.

By the way, it is not that unusual that we do not cover topics as quickly 
as I hope, so this will probably not be the last time we postpone some of
the problems on a problem set.  My objective in 306 is to have everyone 
learn everything by the end of the semester, and sometimes that means going 
over some topics more carefully than I had originally anticipated.  

Good luck with the rest of the course.

Yale Patt