anchor.diff:        value: 5,
         slide: function( event, ui ) {
           $( "#difficulty" ).val( ui.value );
  -        
  +
           $.ajax({
             method: "GET",
             url: "/recipe/filter",
  
positive.code:   });
  </script>
  
  <h2>Recipes</h2>
  <div id="index_filter">
     <div class="difficulty">
      <label for="difficulty">Max Difficulty:</label>
  
negative.code: 
  <div id="index_recipes" class="row">
    <%= render "print_recipes" %>
  </div>
  