English
Let I and J be ideals of a semiring R. Then the product of ideals I · J coincides with their product IJ; equivalently, every element of I · J is a finite sum of products i j with i ∈ I and j ∈ J.
Русский
Пусть I и J — идеалы полуг rings R. Тогда произведение идеалов I · J совпадает с IJ; то есть любой элемент I · J можно представить как конечную сумму произведений i j, где i ∈ I и j ∈ J.
LaTeX
$$$I \\cdot J = I J$$$
Lean4
/-- This duplicates the global `smul_eq_mul`, but doesn't have to unfold anywhere near as much to
apply. -/
protected theorem _root_.Ideal.smul_eq_mul (I J : Ideal R) : I • J = I * J :=
rfl