English
Krull dim equals top iff the order is infinite dimensional.
Русский
Размерность Крулла равна ⊤ тогда и только тогда порядок бесконечно размерный.
LaTeX
$$\operatorname{krullDim}(\alpha) = \top \iff \text{InfiniteDimensionalOrder}(\alpha)$$
Lean4
theorem krullDim_eq_top_iff : krullDim α = ⊤ ↔ InfiniteDimensionalOrder α :=
by
refine ⟨fun h ↦ ?_, fun _ ↦ krullDim_eq_top⟩
cases isEmpty_or_nonempty α
· simp [krullDim_eq_bot] at h
cases finiteDimensionalOrder_or_infiniteDimensionalOrder α
· rw [krullDim_eq_length_of_finiteDimensionalOrder] at h
cases h
· infer_instance