English
The same upper bound with a lifted interpretation: if the sum ≤ κ, then # (WType β) ≤ κ.
Русский
Та же верхняя граница с подъемом: если сумма ≤ κ, то #(WType β) ≤ κ.
LaTeX
$$$#(WType(β)) ≤ κ \Leftarrow (\sum_{a:\alpha} κ ^ #(β a)) ≤ κ.$$$
Lean4
/-- `#(WType β)` is the least cardinal `κ` such that `sum (fun a : α ↦ κ ^ #(β a)) ≤ κ` -/
theorem cardinalMk_le_of_le {κ : Cardinal.{u}} (hκ : (sum fun a : α => κ ^ #(β a)) ≤ κ) : #(WType β) ≤ κ :=
cardinalMk_le_of_le' <| by simp_rw [lift_id]; exact hκ