ui-validate test

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<script src="https://rawgit.com/angular-ui/ui-utils/master/modules/validate/validate.js"></script>
<div ng-app="ui-validate-test">
  <div class="panel" ng-controller="AppController">
     <form name="testForm">
            <input type="number" step="any"
               data-ng-model="candidate.remuneration_from"
               name="remuneration_from" class="form-control"
               id="remuneration_from" min="0" placeholder="Base"
               ui-validate="{lowerBound: '$value <= candidate.remuneration_to', exist:     'exist(candidate.remuneration_to)'}"
               ui-validate-watch=" 'candidate.remuneration_to' "/>
            <input type="number" step="any"
               data-ng-model="candidate.remuneration_to"
               name="remuneration_to" class="form-control" min="0" placeholder="Top"
               ui-validate="{upperBound: '$value >= candidate.remuneration_form', exist:     'exist(candidate.remuneration_from)'}"
               ui-validate-watch=" 'candidate.remuneration_from' "/>
     </form> 
      <label class="text-danger" ng-if="remuneration_from.$error.lowerBound && remuneration_from.$error.exist">
          Base value can't be higher than Top value.
      </label>
      <label class="text-danger" ng-if="remuneration_to.$error.upperBound && remuneration_to.$error.exist">
          Top value can't be lower than Base value.
      </label>
        <p>{{ candidate }}</p>
        <p>Remuneration from:{{ testForm.remuneration_from.$error }}</p>
        <p>Remuneration to:{{ testForm.remuneration_to.$error }}</p>
  </div>
</div>

JavaScript

angular.module('ui-validate-test', ['ui.validate'])
.controller('AppController', function($scope){
    $scope.candidate = {
        'remuneration_from': 10,
        'remuneration_to': 10
    };
    $scope.exist = function(value){
        return ((value === undefined) || (value === null))
    }
});