theorem Parenting.instYoungParentAtToParent
theorem Parenting.instYoungParentAtToParent: ∀ (x t : Type) [YoungParent.At x t], Person.At x t
theorem Parenting.instYoungParentAtToParent
theorem Parenting.instYoungParentAtToParent: ∀ (x t : Type) [YoungParent.At x t], Person.At x t