Open Book:
  type: task
  definitions: book
  speed: 0
  script:
    - inventory close
    - define PrevItem <player.item_in_hand||i@air>
    - inventory set o:<def[Book]> d:<player.inventory> slot:<player.item_in_hand.slot>
    - adjust <player> open_book
    - inventory set o:<def[PrevItem]> d:<player.inventory> slot:<player.item_in_hand.slot>