English
The product map respects smul: prod(m • w) = m · prod(w).
Русский
Производственная карта сохраняет smul: prod(m • w) = m · prod(w).
LaTeX
$$$$ prod( m \\cdot w ) = m \\cdot prod(w) $$$$
Lean4
@[simp]
theorem prod_smul (m) : ∀ w : Word M, prod (m • w) = m * prod w := by
induction m using CoprodI.induction_on with
| one =>
intro
rw [one_smul, one_mul]
| of _ =>
intros
rw [of_smul_def, prod_rcons, of.map_mul, mul_assoc, ← prod_rcons, ← equivPair_symm, Equiv.symm_apply_apply]
| mul x y hx hy =>
intro w
rw [mul_smul, hx, hy, mul_assoc]