anchor.diff:      sign_in @user
     </pre>
   
  -  Finally OpenDSA parses RST files and fetches the names of all exercises and
  +  Finally, OpenDSA parses RST files and fetches the names of all exercises and
     shows the "<em>lti_resource</em>" layout, which opens
     "<em>views/lti/resource.html.haml</em>". The names of these exercises will be
     later shown to instructors in a tree view from where they can select
  
positive.code:             = submit_tag 'Submit', class: 'btn btn-primary'
  
      </pre>
      The code above is just to display a form in which OpenDSA checks if the
      course offering is blank or not. If it is blank then that means that a
      first exercise is being added for this course and no information of this
      particular course is present in OpenDSA's database. To get the information
      about this course, OpenDSA shows a form to track the course and associate
      exercises with that course. <br><br>
  
      Most of the work here is done through the JavaScript
  
negative.code:     <p>
        Previously we have described <%= link_to "here", lti_opendsa_path %> how
        OpenDSA implements LTI when a student tries to access an OpenDSA exercise
        from within an LTI tool consumer such as Canvas or Moodle. This tutorial
        explains how OpenDSA makes use of LTI to support an instructor who wishes
        to add individual OpenDSA visualizations or exercises to their course. To
        better understand this example, you should first try out the instructions
        that instructors will use to incorporate such materials into their
  