English
The symmetry of the dual antidistrib swaps the left and right components via the duality: (sumLexDualAntidistrib α β).symm (inl (toDual b)) = toDual (inr b).
Русский
Симметрия двойственного антираспределителя меняет левую и правую части через двойственность: (sumLexDualAntidistrib α β).symm (inl (toDual b)) = toDual (inr b).
LaTeX
$$$\\bigl(\\text{sumLexDualAntidistrib}_{\\alpha,\\beta}\\bigr)^{-1}(\\mathrm{inl}(\\mathrm{toDual}(b))) = \\mathrm{toDual}(\\mathrm{inr}(b))$$$
Lean4
@[simp]
theorem sumLexDualAntidistrib_inr : sumLexDualAntidistrib α β (toDual (inr b)) = inl (toDual b) :=
rfl