title: How do I define a reducer at the top level?
body: <p>I have two reducer files that handle the two areas of state in my module...</p>
  
  <pre><code>export interface MyState {
    people: PeopleState;
    pets: PetState;
  }
  
  export const reducers: ActionReducerMap&lt;MyState&gt; = {
    people: peopleReducer,
    pets: petsReducer
  };
  </code></pre>
  
  <p>This works fine.  However, I have some actions that need to update both areas of the state.  I'd like to handle this by having a reducer file that deals with things at the MyState level and can update people and pets.  I'd like to keep both the existing reducers that handle this at the lower levels.</p>
  
  <p>I can't see how to register the top level reducer.  The way the code is now, any reducer added to the ActionReducerMap must be added as a property inside MyState rather than handling MyState as a whole.</p>
  
  <p>Anyone got any ideas?</p>
  
  <p>Thanks
  Nick</p>