     $(selector, @el)
 
   bind: =>
-    @el.find('.problem > div').each (index, element) =>
-      MathJax.Hub.Queue ["Typeset", MathJax.Hub, element]
+    if MathJax?
+      @el.find('.problem > div').each (index, element) =>
+        MathJax.Hub.Queue ["Typeset", MathJax.Hub, element]
 
     window.update_schematics()
 


    # Dynamath
    @$('input.math').keyup(@refreshMath)
    @$('input.math').each (index, element) =>
      MathJax.Hub.Queue [@refreshMath, null, element]

  updateProgress: (response) =>
    if response.progress_changed

      $("##{element.id}_dynamath").val(jax.root.toMathML '')
    catch exception
      throw exception unless exception.restart
      if MathJax?
        MathJax.Callback.After [@refreshMath, jax], exception.restart

  refreshAnswers: =>
    @$('input.schematic').each (index, element) ->
