<Provided by &EXT() and set external to the resource, required>
resource.opendate   #unix time of when the local machine should let the
                    #student in

resource.duedate    #unix time of when the local machine should stop
                    #accepting answers

resource.answerdate #unix time of when the local machine should
                    #provide the correct answer to the student

resource.weight     # points the problem is worth

resource.maxtries   # maximum number of attempts the student can have


<caparesponse needed: (has a default if nonexistant)>

resource.tolerance  # lots of possibilities here
                    # percentage, range (inclusive and exclusive),
		    # variable name, etc

resource.significantfigures  # one or two integers

resource.feedback   # at least a single bit (yes/no) may go with a
                    # bitmask in the future


<Problem sets using cstore (required):>
resource.solved # if not set, problem yet to be viewed
                # 0 == incorrect and attempted
                # 1 == correct by student work
                # 2 == correct, instructor override
                # -1 == incorrect, instructor override
                # E == excused, problem no longer counts for student

resource.tries  # positive integer of number of unsuccessful attempts
                # made, malformed answers don't count if feedback is
                # on

resource.awarded # float between 0 and 1, percentage of
                 # resource.weight that the stundent earned.

resource.submissons # list of all of the student submitted strings for all of
                    # answers in the part

resource.awarddetail # list of all of the results of grading the submissions
                     # in detailed form of the specific failure