# mathlibdocumentation

ring_theory.prime

# Prime elements in rings #

This file contains lemmas about prime elements of commutative rings.

theorem mul_eq_mul_prime_prod {R : Type u_1} {α : Type u_2} [decidable_eq α] {x y a : R} {s : finset α} {p : α → R} (hp : ∀ (i : α), i sprime (p i)) (hx : x * y = a * s.prod (λ (i : α), p i)) :
∃ (t u : finset α) (b c : R), t u = s u a = b * c x = b * t.prod (λ (i : α), p i) y = c * u.prod (λ (i : α), p i)

If x * y = a * ∏ i in s, p i where p i is always prime, then x and y can both be written as a divisor of a multiplied by a product over a subset of s

theorem mul_eq_mul_prime_pow {R : Type u_1} {x y a p : R} {n : } (hp : prime p) (hx : x * y = a * p ^ n) :
∃ (i j : ) (b c : R), i + j = n a = b * c x = b * p ^ i y = c * p ^ j

If x * y = a * p ^ n where p is prime, then x and y can both be written as the product of a power of p and a divisor of a.

theorem prime.neg {α : Type u_1} [comm_ring α] {p : α} (hp : prime p) :
prime (-p)
theorem prime.abs {α : Type u_1} [comm_ring α] [linear_order α] {p : α} (hp : prime p) :