English
There is an IsScalarTower Int R M, i.e. the integers act compatibly with the R-action on M: (n • r) • m = n • (r • m) for all n ∈ ℤ, r ∈ R, m ∈ M.
Русский
Существует IsScalarTower Int R M: целые числа действуют согласованно с действием R на M: (n • r) • m = n • (r • m).
LaTeX
$$$\\mathrm{IsScalarTower}\\ \\mathbb{Z}\\ R\\ M$$$
Lean4
instance intIsScalarTower {R : Type u} {M : Type v} [Ring R] [AddCommGroup M] [Module R M] : IsScalarTower ℤ R M where
smul_assoc n x
y := by
cases n with
| ofNat => simp [mul_smul, Nat.cast_smul_eq_nsmul]
| negSucc => simp [mul_smul, add_smul, Nat.cast_smul_eq_nsmul]