** Using WeBWorK **

## DESCRIPTION
## I am trying to debug why an empty set or singleton set is not acceptable as an answer
## ENDDESCRIPTION
DOCUMENT();
loadMacros('PGstandard.pl', 'PGML.pl',"MathObjects.pl",'PGcourse.pl');
Context("Interval"); # without this line, the empty set and singletons are not accepted
@mylist0 = ();
@mylist1 = (7);
@mylist2 = (7,13);
$ans0 = Set(@mylist0);
$ans1 = Set(@mylist1);
$ans2 = Set(@mylist2);
$ans3 = Set();
$ans4 = Set(7); #
$ans5 = Set(7,13);
$ans6 = Set("7");
$ans7 = Set("{7}");
$ans8 = Set("{7}");
BEGIN_PGML
The answer is the empty set [` X_0 = `][_]{$ans0}
The answer is the set {7} [` X_1 = `][_]{$ans1}
The answer is the set {7,13} [` X_2 = `][_]{$ans2}
The answer is the empty set [` X_3 = `][_]{$ans3}
The answer is the set {7} [` X_4 = `][_]{$ans4->cmp(requireParenMatch => 0, implicitList => 0)}
The answer is the set {7,13} [` X_5 = `][_]{$ans5->cmp(requireParenMatch => 0, implicitList => 0)}
The answer is the set {7} [` X_6 = `][_]{$ans6->cmp(requireParenMatch => 0, implicitList => 0)}
The answer is the set {7} [` X_7 = `][_]{$ans7->cmp(requireParenMatch => 0, implicitList => 0)}
END_PGML
BEGIN_TEXT
\($ans8\) = \{$ans8->ans_rule\}
END_TEXT
ANS($ans8->cmp);
ENDDOCUMENT();