Redux/reselect selector function arguments explanation?

Question

I am working on a codebase written in Typescript that uses a lot of immutable reselect. I haven't been working with reselect yet and I have come across an example that I don't understand:

export const panelsSelector: (
  order: Order,
  events: List<List<Event>>,
  adminRole: boolean,
  packageEvents: List<List<PackageEvent>>,
) => List<PanelProps> = createImmutableEqualSelector(
  (order: Order) => order,
  (order: Order, events: List<List<Event>>) => events,
  (order: Order, events: List<List<Event>>, adminRole: boolean) => adminRole,
  (order: Order, events: List<List<Event>>, adminRole: boolean, packageEvents: List<List<PackageEvent>>) => packageEvents,
  (order, events, adminRole, packageEvents) => List<PanelProps>([
      {
        content: <Events packageEvents={packageEvents}
                         events={events}
                 />
      },
      {
        content: <MyComponent  packages={order.get('packages')}
                               adminRole={adminRole}
                               packagesCount={order.get('noOfPackages')}/>
      },
)

If I am reading this right panelsSelector is assigned I guess an anonymous type which is a function. In this case I guess createImmutableEqualSelector returns a function which returns List<PanelProps>. To simplify something like this:

const panelsSelector:(arg) => List<PanelProps> = createImmutableEqualSelector((arg) => List<PanelProps>)

What I don't understand in this example is why the selectors need to have an argument added from its predecessor to an argument list?

  (order: Order) => order,
  (order: Order, events: List<List<Event>>) => events,
  (order: Order, events: List<List<Event>>, adminRole: boolean) => adminRole,
  (order: Order, events: List<List<Event>>, adminRole: boolean, packageEvents: List<List<PackageEvent>>) => packageEvents

If I remove an argument from a predecessor for example for the second selector:

(events: List<List<Event>>) => events

I get a typescript error:

Types of parameters 'state' and 'order' are incompatible.

So, why do this selectors need to be written like that? So far I have only seen simple examples like this one where we get the data from the state:

const selectShopItems = state => state.shop.items

But, I don't understand the former example. If order is not state, then where is that data coming from?