English
Under two Galois connections, the image infimum equals a double-infimum composition.
Русский
При двух Гало-соединениях образ инфимума равен двойной композиции инфимума.
LaTeX
$$$(h_1 : ∀ b, GaloisConnection (l_1 b) (swap u b)) (h_2 : ∀ a, GaloisConnection (l_2 a) (u a)) : s.Nonempty → BddBelow s → t.Nonempty → BddAbove t → sInf (image2 u s t) = u (sInf s) (sInf t)$$$
Lean4
noncomputable instance completeLattice {α : Type*} [ConditionallyCompleteLattice α] :
CompleteLattice (WithBot (WithTop α)) :=
{ instInfSet, instSupSet, instBoundedOrder,
lattice with
le_sSup := (WithTop.WithBot.completeLattice (α := αᵒᵈ)).sInf_le
sSup_le := (WithTop.WithBot.completeLattice (α := αᵒᵈ)).le_sInf
sInf_le := (WithTop.WithBot.completeLattice (α := αᵒᵈ)).le_sSup
le_sInf := (WithTop.WithBot.completeLattice (α := αᵒᵈ)).sSup_le }