app-todos.component.ts

@Component({
  selector: 'my-app',
  template: `
    <b>default</b>: {{ todos$ | async | json }} <br>
    <b>mutable reverse</b>: {{ mutableTodos$ | async | json }} <br>
    <b>immutable reverse</b>: {{ immutableTodos$ | async | json }} <br>
  `
})
export class AppComponent  {

  @Select(AppState) 
  public todos$: Observable<number[]>;

  @Select(AppState.mutableTodos) 
  public mutableTodos$: Observable<number[]>;

  @Select(AppState.immutableTodos) 
  public immutableTodos$: Observable<number[]>;
  
}