English
Mapping by an embedding f commutes with sym2: (s.map f).sym2 = s.sym2.map (Sym2.map f).
Русский
Отображение через вложение f гармонирует с sym2: (s.map f).sym2 = s.sym2.map (Sym2.map f).
LaTeX
$$$(s.map f)^{\!\text{sym2}} = s^{\!\text{sym2}}.map(\text{Sym2.map } f)$$$
Lean4
theorem sym2_map (f : α ↪ β) (s : Finset α) : (s.map f).sym2 = s.sym2.map (.sym2Map f) :=
val_injective <| s.val.sym2_map _