drothlis/pretty-symbols — pull request #14 by DarwinAwardWinner (2014-08-13 21:40:06+00:00)
Title: Improve custom declaration and add new pretty symbol

The first commit improves the custom declatation for `pretty-symbol-categories` to put the standard categories in a checklist but allow addition of arbitrary other categories.

The second commit adds a new "nil" category that replaces "nil" with the null set symbol in lisps.