English
Under an affine equivalence, SOppSide respects the image: (s.map ↑f).SOppSide (f x) (f y) ↔ s.SOppSide x y.
Русский
При аффинной эквивалентности SOppSide сохраняется в образе.
LaTeX
$$$$ (s.map ↑f).SOppSide (f x) (f y) \iff s.SOppSide x y. $$$$
Lean4
theorem _root_.Function.Injective.sOppSide_map_iff {s : AffineSubspace R P} {x y : P} {f : P →ᵃ[R] P'}
(hf : Function.Injective f) : (s.map f).SOppSide (f x) (f y) ↔ s.SOppSide x y := by
simp_rw [SOppSide, hf.wOppSide_map_iff, mem_map_iff_mem_of_injective hf]