** Using WeBWorK **

I believe that ProblemRandomize does not correctly dispose of previous information when the MultiAnswer parser is used.  Below is an example .pg code that illustrates this issue.  When a correct answer is submitted and then a new random problem is requested, the first answer blank for the MultiAnswer is cleared, but the second answer blank continues to show the most recent submitted answer.

I went to see if I could see an obvious solution, but I realized I would need to understand how WW maintains information between queries.  I thought someone else might be better suited to find the error.

Brian Walton
James Madison University

-----------------

DOCUMENT();        # This should be the first executable line in the problem.

loadMacros(
  "PGstandard.pl",
  "MathObjects.pl",
  "parserMultiAnswer.pl",
  "problemRandomize.pl"
);

TEXT(beginproblem);

###################################
# Setup

Context("Numeric");
$pr = ProblemRandomize(onlyAfterDue=>0);

# Answer
$k = random(10,20);

$exA = Real(random(1,$k-1,1));
$exB = Real($k-$exA);

$multipart = MultiAnswer($exA, $exB)->with(
    singleResult => 1,
    checker => sub {
        my ( $correct, $student, $self ) = @_;
        my ( $stuA, $stuB ) = @{$student};
        my ( $exA, $exB ) = @{$student};
       
        $zero = Real(0);
        if ($stuA == $zero) {
            $self->setMessage(1, "Do not use zero.");
            return 0;
        } elsif ($stuB == $zero) {
            $self->setMessage(2, "Do not use zero.");
            return 0;
        } else {
            return ($stuA+$stuB == $exA+$exB);
        }
    }
);

BEGIN_TEXT
Give two non-zero numbers \(a\) and \(b\) so that \(a+b = $k\).

$PAR
\(a = \)\{ $multipart->ans_rule(5) \}
and
\(b = \) \{ $multipart->ans_rule(5) \}.
END_TEXT

###################################
# Answer checking

$showPartialCorrectAnswers = 0;
ANS($multipart->cmp);

###################################

ENDDOCUMENT();        # This should be the last executable line in the problem.;