Theorem isufd 33621

Description: The property of being a Unique Factorization Domain. (Contributed by Thierry Arnoux, 1-Jun-2024.)

Hypotheses

Ref	Expression
isufd.i	⊢ 𝐼 = (PrmIdeal‘𝑅)
isufd.3	⊢ 𝑃 = (RPrime‘𝑅)
isufd.0	⊢ 0 = (0g‘𝑅)

Assertion

Ref	Expression
isufd	⊢ (𝑅 ∈ UFD ↔ (𝑅 ∈ IDomn ∧ ∀𝑖 ∈ (𝐼 ∖ {{ 0 }})(𝑖 ∩ 𝑃) ≠ ∅))

Distinct variable group:   𝑅,𝑖

Allowed substitution hints:   𝑃(𝑖)   𝐼(𝑖)   0 (𝑖)

Proof of Theorem isufd

Dummy variable 𝑟 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		fveq2 6834	. . . . 5 ⊢ (𝑟 = 𝑅 → (PrmIdeal‘𝑟) = (PrmIdeal‘𝑅))
2		isufd.i	. . . . 5 ⊢ 𝐼 = (PrmIdeal‘𝑅)
3	1, 2	eqtr4di 2789	. . . 4 ⊢ (𝑟 = 𝑅 → (PrmIdeal‘𝑟) = 𝐼)
4		fveq2 6834	. . . . . . 7 ⊢ (𝑟 = 𝑅 → (0g‘𝑟) = (0g‘𝑅))
5		isufd.0	. . . . . . 7 ⊢ 0 = (0g‘𝑅)
6	4, 5	eqtr4di 2789	. . . . . 6 ⊢ (𝑟 = 𝑅 → (0g‘𝑟) = 0 )
7	6	sneqd 4592	. . . . 5 ⊢ (𝑟 = 𝑅 → {(0g‘𝑟)} = { 0 })
8	7	sneqd 4592	. . . 4 ⊢ (𝑟 = 𝑅 → {{(0g‘𝑟)}} = {{ 0 }})
9	3, 8	difeq12d 4079	. . 3 ⊢ (𝑟 = 𝑅 → ((PrmIdeal‘𝑟) ∖ {{(0g‘𝑟)}}) = (𝐼 ∖ {{ 0 }}))
10		fveq2 6834	. . . . . 6 ⊢ (𝑟 = 𝑅 → (RPrime‘𝑟) = (RPrime‘𝑅))
11		isufd.3	. . . . . 6 ⊢ 𝑃 = (RPrime‘𝑅)
12	10, 11	eqtr4di 2789	. . . . 5 ⊢ (𝑟 = 𝑅 → (RPrime‘𝑟) = 𝑃)
13	12	ineq2d 4172	. . . 4 ⊢ (𝑟 = 𝑅 → (𝑖 ∩ (RPrime‘𝑟)) = (𝑖 ∩ 𝑃))
14	13	neeq1d 2991	. . 3 ⊢ (𝑟 = 𝑅 → ((𝑖 ∩ (RPrime‘𝑟)) ≠ ∅ ↔ (𝑖 ∩ 𝑃) ≠ ∅))
15	9, 14	raleqbidv 3316	. 2 ⊢ (𝑟 = 𝑅 → (∀𝑖 ∈ ((PrmIdeal‘𝑟) ∖ {{(0g‘𝑟)}})(𝑖 ∩ (RPrime‘𝑟)) ≠ ∅ ↔ ∀𝑖 ∈ (𝐼 ∖ {{ 0 }})(𝑖 ∩ 𝑃) ≠ ∅))
16		df-ufd 33620	. 2 ⊢ UFD = {𝑟 ∈ IDomn ∣ ∀𝑖 ∈ ((PrmIdeal‘𝑟) ∖ {{(0g‘𝑟)}})(𝑖 ∩ (RPrime‘𝑟)) ≠ ∅}
17	15, 16	elrab2 3649	1 ⊢ (𝑅 ∈ UFD ↔ (𝑅 ∈ IDomn ∧ ∀𝑖 ∈ (𝐼 ∖ {{ 0 }})(𝑖 ∩ 𝑃) ≠ ∅))

Syntax hints:   ↔ wb 206   ∧ wa 395   = wceq 1541   ∈ wcel 2113   ≠ wne 2932  ∀wral 3051   ∖ cdif 3898   ∩ cin 3900  ∅c0 4285  {csn 4580  ‘cfv 6492  0_gc0g 17359  RPrimecrpm 20368  IDomncidom 20626  PrmIdealcprmidl 33516  UFDcufd 33619

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-8 2115  ax-9 2123  ax-ext 2708

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1544  df-fal 1554  df-ex 1781  df-sb 2068  df-clab 2715  df-cleq 2728  df-clel 2811  df-ne 2933  df-ral 3052  df-rab 3400  df-v 3442  df-dif 3904  df-un 3906  df-in 3908  df-ss 3918  df-nul 4286  df-if 4480  df-sn 4581  df-pr 4583  df-op 4587  df-uni 4864  df-br 5099  df-iota 6448  df-fv 6500  df-ufd 33620

This theorem is referenced by:  ufdprmidl  33622  ufdidom  33623  pidufd  33624  1arithufdlem4  33628  dfufd2  33631