theorem BFO.MaterialEntity.At.toParent
theorem BFO.MaterialEntity.At.toParent: ∀ (x t : Type) [At x t], IndependentContinuant.At x t
theorem BFO.MaterialEntity.At.toParent
theorem BFO.MaterialEntity.At.toParent: ∀ (x t : Type) [At x t], IndependentContinuant.At x t