anchor.diff:      var siblings = $A(thisArm.parentNode.getElementsByTagName("LI"))
   
       updateMoveControlVisibility('arm', thisArm.id.split('-')[1], thisArm, siblings)
  +    updateDeleteControlVisibility('arm', siblings);
   }
   
   function updateAllArmsControlVisibility(epochId) {
  -    $$('#epoch-' + epochId + '-arms li').each(updateArmControlVisibility)
  +    var armItems = $$('#epoch-' + epochId + '-arms li');
  +    armItems.each(updateArmControlVisibility)
   }
   
   function createStudyControls() {
  
positive.code:     }
      href += objectType + '=' + objectId
      var a = Builder.node("a", {
          className: objectType + '-control control',
          id: objectType + "-" + objectId + "-" + controlName,
          href: href
      })
  
negative.code:     } else {
          upControl.show(); downControl.show();
      }
  }
  
  function updateDeleteControlVisibility(objectType, elts) {
      var controls = $$('.' + objectType + '-delete-control')
      if (elts.length <= 1) {
          controls.each(function(c) { c.hide() })
      } else {
          controls.each(function(c) { c.show() })
      }
  }