<a class="dropdown-toggle" ng-class="{'disabled': agenda.items().length <= 0 }" data-toggle="dropdown" role="button"
   aria-haspopup="true" aria-expanded="false">Propositional <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="Exhaustive" code-name="prop" exec="doTactic(undefined, codeName)"></k4-tactic-menu-entry>
    <k4-tactic-menu-entry
          