Theorem: irreducible_iff_prime_of_exists_unique_irreducible_factors
File: Mathlib/RingTheory/UniqueFactorizationDomain.lean

Proof steps:
state_before: α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : a * b = 0
ha0 : a = 0
⊢ p ∣ a ∨ p ∣ b
state_after: no goals
tactic: simp [ha0]
state_before: α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : a * b = 0
hb0 : b = 0
⊢ p ∣ a ∨ p ∣ b
state_after: no goals
tactic: simp [hb0]
state_before: α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
⊢ p ∣ a ∨ p ∣ b
state_after: α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
⊢ p ∣ a ∨ p ∣ b
tactic: have hx0 : x ≠ 0 := fun hx0 => by simp_all
state_before: α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
⊢ p ∣ a ∨ p ∣ b
state_after: α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
ha0 : a ≠ 0
⊢ p ∣ a ∨ p ∣ b
tactic: have ha0 : a ≠ 0 := left_ne_zero_of_mul hab0
state_before: α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
ha0 : a ≠ 0
⊢ p ∣ a ∨ p ∣ b
state_after: α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
ha0 : a ≠ 0
hb0 : b ≠ 0
⊢ p ∣ a ∨ p ∣ b
tactic: have hb0 : b ≠ 0 := right_ne_zero_of_mul hab0
state_before: α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
ha0 : a ≠ 0
hb0 : b ≠ 0
⊢ p ∣ a ∨ p ∣ b
state_after: case intro
α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
ha0 : a ≠ 0
hb0 : b ≠ 0
fx : Multiset α
hfx : (∀ b ∈ fx, Irreducible b) ∧ fx.prod ~ᵤ x
⊢ p ∣ a ∨ p ∣ b
tactic: cases' eif x hx0 with fx hfx
state_before: case intro
α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
ha0 : a ≠ 0
hb0 : b ≠ 0
fx : Multiset α
hfx : (∀ b ∈ fx, Irreducible b) ∧ fx.prod ~ᵤ x
⊢ p ∣ a ∨ p ∣ b
state_after: case intro.intro
α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
ha0 : a ≠ 0
hb0 : b ≠ 0
fx : Multiset α
hfx : (∀ b ∈ fx, Irreducible b) ∧ fx.prod ~ᵤ x
fa : Multiset α
hfa : (∀ b ∈ fa, Irreducible b) ∧ fa.prod ~ᵤ a
⊢ p ∣ a ∨ p ∣ b
tactic: cases' eif a ha0 with fa hfa
state_before: case intro.intro
α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
ha0 : a ≠ 0
hb0 : b ≠ 0
fx : Multiset α
hfx : (∀ b ∈ fx, Irreducible b) ∧ fx.prod ~ᵤ x
fa : Multiset α
hfa : (∀ b ∈ fa, Irreducible b) ∧ fa.prod ~ᵤ a
⊢ p ∣ a ∨ p ∣ b
state_after: case intro.intro.intro
α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
ha0 : a ≠ 0
hb0 : b ≠ 0
fx : Multiset α
hfx : (∀ b ∈ fx, Irreducible b) ∧ fx.prod ~ᵤ x
fa : Multiset α
hfa : (∀ b ∈ fa, Irreducible b) ∧ fa.prod ~ᵤ a
fb : Multiset α
hfb : (∀ b ∈ fb, Irreducible b) ∧ fb.prod ~ᵤ b
⊢ p ∣ a ∨ p ∣ b
tactic: cases' eif b hb0 with fb hfb
state_before: case intro.intro.intro
α : Type u_1
inst✝ : CancelCommMonoidWithZero α
eif : ∀ (a : α), a ≠ 0 → ∃ f, (∀ b ∈ f, Irreducible b) ∧ f.prod ~ᵤ a
uif :
  ∀ (f g : Multiset α),
    (∀ x ∈ f, Irreducible x) → (∀ x ∈ g, Irreducible x) → f.prod ~ᵤ g.prod → Multiset.Rel Associated f g
p : α
this : DecidableEq α := Classical.decEq α
hpi : Irreducible p
a b : α
x✝ : p ∣ a * b
x : α
hx : a * b = p * x
hab0 : ¬a * b = 0
hx0 : x ≠ 0
ha0 : a ≠ 0
hb0 : b ≠ 0
fx : Multiset α
hfx : (∀ b ∈ fx, Irreducible b) ∧ fx.prod ~ᵤ x
fa : Multiset α
hfa : (∀ b ∈ fa, Irreducible b) ∧ fa.prod ~ᵤ a
fb : Multiset α
hfb : (∀ b ∈ fb, Irreducible b) ∧ fb.prod ~ᵤ b
h : Multiset.Rel Associated (p ::ₘ fx) (fa + fb)
⊢ p ∣ a ∨ p ∣ b
state_after: no goals
tactic: exact
          let ⟨q, hqf, hq⟩ := Multiset.exists_mem_of_rel_of_mem h (Multiset.mem_cons_self p _)
          (Multiset.mem_add.1 hqf).elim
            (fun hqa =>
              Or.inl <| hq.dvd_iff_dvd_left.2 <| hfa.2.dvd_iff_dvd_right.1 (Multiset.dvd_prod hqa))
            fun hqb =>
            Or.inr <| hq.dvd_iff_dvd_left.2 <| hfb.2.dvd_iff_dvd_right.1 (Multiset.dvd_prod hqb)