The problem: a student forgets the +C, gets marked incorrect with the message, "Your answer is not the most general solution." Student adds +C, gets marked correct, with the message, "This answer is equivalent to the one you just submitted." Except of course, that the two answers are not equivalent - one is wrong while one is right.
Can I modify parserFormulaUpToConstant.pl to suppress that message, or to not check the student's previous answer, and put it in my macros folder to fix this?