```kotlin
val indoorLocationManager = IndoorLocationManager.create(applicationContext, officeLobby)

indoorLocationManager.setOnPositionUpdateListener(object : OnPositionUpdateListener() {
  override fun onPositionUpdate(locationPosition: LocationPosition) {
    if (locationPosition.distanceTo(entrance) < 3) {
      displayWelcomeNotification("Hello, Physical World!")
    }
  }
})

indoorLocationManager.startPositioning()
```