<a class="dropdown-toggle" ng-class="{'disabled': agenda.items().length <= 0 }" data-toggle="dropdown" role="button"
   aria-haspopup="true" aria-expanded="false" disabledtooltip="First-order Logic">Quantifier <span class="caret"></span></a>
<ul class="dropdown-menu">
    <k4-tactic-menu-entry
            disabled="agenda.items().length <= 0"
            proof-id="{{proofId}}" user-id="{{userId}}"
            name="&forall;R" code-name="allR"
            exec="openTacticPosInputDialog(codeName, 'R')" option