English
For x ∈ WithTop α and y ∈ WithTop (OrderDual α), x ≤ ofDual y is equivalent to y ≤ x (under the dualization).
Русский
Для x ∈ WithTop α и y ∈ WithTop (OrderDual α) имеет место: x ≤ ofDual(y) эквивалентно y ≤ x (после двойственности).
LaTeX
$$$ x \le \mathrm{WithTop.ofDual}(y) \iff y \le x. $$$$
Lean4
theorem le_ofDual_iff {x : WithBot α} {y : WithTop αᵒᵈ} : x ≤ WithTop.ofDual y ↔ y ≤ x.toDual := by
cases x <;> cases y <;> simp [le_toDual]