theorem BFO.SpatiotemporalRegion.At.toParent
theorem BFO.SpatiotemporalRegion.At.toParent: ∀ (x t : Type) [At x t], Occurrent.At x t
theorem BFO.SpatiotemporalRegion.At.toParent
theorem BFO.SpatiotemporalRegion.At.toParent: ∀ (x t : Type) [At x t], Occurrent.At x t