Khan/khan-exercises — pull request #8057 by smenks13 (2011-12-07 20:38:53+00:00)
Title: Substitution rewind, added abs() to data-ensure to handle special cases

Added the data-ensures back to keep numbers small, and I think I handled the cases that were causing problems as well by making sure abs( X ) !== abs( Y )

I tried the bad seeds that were in the issues, and they work now.