edx/edx-platform — pull request #2667 by ichuang (2014-02-21 02:10:35+00:00)
Title: add infinity symbol to calc preview

formulaequationinput should accept the standard infinity notation of asciimath, `infty`.

This PR fixes this issue.

See analogous fix for hbar: https://github.com/edx/edx-platform/pull/888