English
Multiplication by n is a polynomial function in Witt coordinates; the underlying is Poly in p and coefficients.
Русский
Умножение на n является полиномной функцией по координатам Witt; основание — полином в p и коэффициентах.
LaTeX
$$@[is_poly] theorem mulN_isPoly (n) : IsPoly p (fun _ _Rcr x => x * n)$$
Lean4
/-- Multiplication by `n` is a polynomial function. -/
@[is_poly]
theorem mulN_isPoly (n : ℕ) : IsPoly p fun _ _Rcr x => x * n :=
⟨⟨wittMulN p n, fun R _Rcr x => by funext k; exact mulN_coeff n x k⟩⟩