I would like to allow nonreduced and non simplified unions in some answers. I have looked around and I am struggling to find a way to do this. I can see that by default, Interval context requires simplified unions, but I am trying to find a way to avoid that. I have attempted to add the line
Context()->flags->set(reduceUnions => 0);
but to no avail. I have also attempted to play around with the reduceUnionsForComparision but I also cannot get that to work. Any ideas? Here is a simple example where I would love students to be able to enter either {1,6}U{2,5} OR {1}U{2,5}U{6}
###########################
# Initialization
DOCUMENT();
loadMacros(
"PGstandard.pl",
"MathObjects.pl",
"PGML.pl",
);
TEXT(beginproblem());
##########################
# Setup
Context("Interval");
$a = Interval("{1}U(2,5)U{6}");
BEGIN_PGML
the interval [`[$a]`] is [_]{$a}
END_PGML
COMMENT('Uses PGML.');
ENDDOCUMENT();