Hello,
I was looking at your example for making the power set of {red,green}. I added the following code so potential students could see the correct answer :
BEGIN_PGML_SOLUTION
The answer is [$ans].
END_PGML_SOLUTION
However, the solution displayed is
( Instructor solution preview: show the student solution after due date. )
The answer is {{}, {0}, {1}, {0,1}}.
Can you let me know why the answer is displayed incorrectly? Thank-you!
Cindy