English
Subtracting a vecCons from a vector yields a vecCons of coordinatewise differences.
Русский
Вычитание vecCons из вектора даёт vecCons разностей по координатам.
LaTeX
$$$ v - \mathrm{vecCons} y w = \mathrm{vecCons}(\mathrm{vecHead} v - y) (\mathrm{vecTail} v - w) $$$
Lean4
@[simp]
theorem sub_cons (v : Fin n.succ → α) (y : α) (w : Fin n → α) :
v - vecCons y w = vecCons (vecHead v - y) (vecTail v - w) := by ext i;
refine i.cases ?_ ?_ <;> simp [vecHead, vecTail]