Readonlykey: ScreenItemKeyReadonlylist: stringReadonlyscreen: stringThe item's id.
Readonly_Optional Readonly~effect/Optional Readonly~effect/Optional Readonly~effect/Optional Readonly~effect/Optional Readonly~effect/OptionalcauseReadonlykeyReadonlylistReadonlyscreenThe item's id.
Optionalstack
A trail would record an edge taken from an item whose identity key is not unique in its list (
list,key): a retrace could not tell which item it was, so the key is not an identity and the trail is refused.