'Perspective Transfer Impossibility,' the engine's claim that consciousness cannot be copied.
It holds that uploading a mind produces a copy while the original dies, which undercuts the transhumanist 'merge with the machine' story.
The reasoning: an upload is a copy, so the first-person 'you' doesn't move over — the original simply ends.
The desc uses this to invalidate the transhumanist merge narrative, as a corollary of the engine's BST framework.