toggle-demo

gistfile1.txt

<polymer-element name="demo-element">
  <template>
    <paper-toggle-button checked="{{a}}"></paper-toggle-button>
    <paper-toggle-button checked="{{b}}"></paper-toggle-button>
  </template>
  <script>
    Polymer({
      a: false,
      b: false,
      aChanged: function () {
        if (this.a) {
          this.b = false;
        }
      }
    });
  
  </script>
  
</polymer-element>