English
The product of the coordinates after applying the right transform is contained in the original product: (mulETransformRight e x).1 * (mulETransformRight e x).2 ⊆ x.1 * x.2.
Русский
Произведение координат после правого преобразования содержится в исходном произведении: (mulETransformRight e x).1 * (mulETransformRight e x).2 ⊆ x.1 * x.2.
LaTeX
$$$ (\\mathrm{mulETransformRight}\\, e\\, x).1 \\cdot (\\mathrm{mulETransformRight}\\, e\\, x).2 \\subseteq x.1 \\cdot x.2 $$$
Lean4
@[to_additive]
theorem fst_mul_snd_subset : (mulETransformRight e x).1 * (mulETransformRight e x).2 ⊆ x.1 * x.2 :=
by
refine union_mul_inter_subset_union.trans (union_subset Subset.rfl ?_)
rw [op_smul_finset_mul_eq_mul_smul_finset, smul_inv_smul]