English
For x ∈ WithBot αᵒᵈ and y ∈ WithTop α, x < ToDual y is equivalent to y large too in the dual sense: y < OfDual x.
Русский
Для x ∈ WithBot αᵒᵈ и y ∈ WithTop α, x < toDual(y) эквивалентно y < ofDual(x) в двойственном порядке.
LaTeX
$$$ x < \mathrm{toDual}(y) \iff y < x^{\mathrm{toDual}}. $$$$
Lean4
theorem lt_ofDual_iff {x : WithBot α} {y : WithTop αᵒᵈ} : x < WithTop.ofDual y ↔ y < WithBot.toDual x := by
cases x <;> cases y <;> simp [lt_toDual]