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Type | Label | Description |
---|---|---|
Statement | ||
Theorem | ringn0 19001 | Rings exist. (Contributed by AV, 29-Apr-2019.) |
⊢ Ring ≠ ∅ | ||
Theorem | ringlghm 19002* | Left-multiplication in a ring by a fixed element of the ring is a group homomorphism. (It is not usually a ring homomorphism.) (Contributed by Mario Carneiro, 4-May-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝐵) → (𝑥 ∈ 𝐵 ↦ (𝑋 · 𝑥)) ∈ (𝑅 GrpHom 𝑅)) | ||
Theorem | ringrghm 19003* | Right-multiplication in a ring by a fixed element of the ring is a group homomorphism. (It is not usually a ring homomorphism.) (Contributed by Mario Carneiro, 4-May-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝐵) → (𝑥 ∈ 𝐵 ↦ (𝑥 · 𝑋)) ∈ (𝑅 GrpHom 𝑅)) | ||
Theorem | gsummulc1 19004* | A finite ring sum multiplied by a constant. (Contributed by Mario Carneiro, 19-Dec-2014.) (Revised by AV, 10-Jul-2019.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 0 = (0g‘𝑅) & ⊢ + = (+g‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ (𝜑 → 𝑅 ∈ Ring) & ⊢ (𝜑 → 𝐴 ∈ 𝑉) & ⊢ (𝜑 → 𝑌 ∈ 𝐵) & ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝑋 ∈ 𝐵) & ⊢ (𝜑 → (𝑘 ∈ 𝐴 ↦ 𝑋) finSupp 0 ) ⇒ ⊢ (𝜑 → (𝑅 Σg (𝑘 ∈ 𝐴 ↦ (𝑋 · 𝑌))) = ((𝑅 Σg (𝑘 ∈ 𝐴 ↦ 𝑋)) · 𝑌)) | ||
Theorem | gsummulc2 19005* | A finite ring sum multiplied by a constant. (Contributed by Mario Carneiro, 19-Dec-2014.) (Revised by AV, 10-Jul-2019.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 0 = (0g‘𝑅) & ⊢ + = (+g‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ (𝜑 → 𝑅 ∈ Ring) & ⊢ (𝜑 → 𝐴 ∈ 𝑉) & ⊢ (𝜑 → 𝑌 ∈ 𝐵) & ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝑋 ∈ 𝐵) & ⊢ (𝜑 → (𝑘 ∈ 𝐴 ↦ 𝑋) finSupp 0 ) ⇒ ⊢ (𝜑 → (𝑅 Σg (𝑘 ∈ 𝐴 ↦ (𝑌 · 𝑋))) = (𝑌 · (𝑅 Σg (𝑘 ∈ 𝐴 ↦ 𝑋)))) | ||
Theorem | gsummgp0 19006* | If one factor in a finite group sum of the multiplicative group of a commutative ring is 0, the whole "sum" (i.e. product) is 0. (Contributed by AV, 3-Jan-2019.) |
⊢ 𝐺 = (mulGrp‘𝑅) & ⊢ 0 = (0g‘𝑅) & ⊢ (𝜑 → 𝑅 ∈ CRing) & ⊢ (𝜑 → 𝑁 ∈ Fin) & ⊢ ((𝜑 ∧ 𝑛 ∈ 𝑁) → 𝐴 ∈ (Base‘𝑅)) & ⊢ ((𝜑 ∧ 𝑛 = 𝑖) → 𝐴 = 𝐵) & ⊢ (𝜑 → ∃𝑖 ∈ 𝑁 𝐵 = 0 ) ⇒ ⊢ (𝜑 → (𝐺 Σg (𝑛 ∈ 𝑁 ↦ 𝐴)) = 0 ) | ||
Theorem | gsumdixp 19007* | Distribute a binary product of sums to a sum of binary products in a ring. (Contributed by Mario Carneiro, 8-Mar-2015.) (Revised by AV, 10-Jul-2019.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 0 = (0g‘𝑅) & ⊢ (𝜑 → 𝐼 ∈ 𝑉) & ⊢ (𝜑 → 𝐽 ∈ 𝑊) & ⊢ (𝜑 → 𝑅 ∈ Ring) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐼) → 𝑋 ∈ 𝐵) & ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐽) → 𝑌 ∈ 𝐵) & ⊢ (𝜑 → (𝑥 ∈ 𝐼 ↦ 𝑋) finSupp 0 ) & ⊢ (𝜑 → (𝑦 ∈ 𝐽 ↦ 𝑌) finSupp 0 ) ⇒ ⊢ (𝜑 → ((𝑅 Σg (𝑥 ∈ 𝐼 ↦ 𝑋)) · (𝑅 Σg (𝑦 ∈ 𝐽 ↦ 𝑌))) = (𝑅 Σg (𝑥 ∈ 𝐼, 𝑦 ∈ 𝐽 ↦ (𝑋 · 𝑌)))) | ||
Theorem | prdsmgp 19008 | The multiplicative monoid of a product is the product of the multiplicative monoids of the factors. (Contributed by Mario Carneiro, 11-Mar-2015.) |
⊢ 𝑌 = (𝑆Xs𝑅) & ⊢ 𝑀 = (mulGrp‘𝑌) & ⊢ 𝑍 = (𝑆Xs(mulGrp ∘ 𝑅)) & ⊢ (𝜑 → 𝐼 ∈ 𝑉) & ⊢ (𝜑 → 𝑆 ∈ 𝑊) & ⊢ (𝜑 → 𝑅 Fn 𝐼) ⇒ ⊢ (𝜑 → ((Base‘𝑀) = (Base‘𝑍) ∧ (+g‘𝑀) = (+g‘𝑍))) | ||
Theorem | prdsmulrcl 19009 | A structure product of rings has closed binary operation. (Contributed by Mario Carneiro, 11-Mar-2015.) |
⊢ 𝑌 = (𝑆Xs𝑅) & ⊢ 𝐵 = (Base‘𝑌) & ⊢ · = (.r‘𝑌) & ⊢ (𝜑 → 𝑆 ∈ 𝑉) & ⊢ (𝜑 → 𝐼 ∈ 𝑊) & ⊢ (𝜑 → 𝑅:𝐼⟶Ring) & ⊢ (𝜑 → 𝐹 ∈ 𝐵) & ⊢ (𝜑 → 𝐺 ∈ 𝐵) ⇒ ⊢ (𝜑 → (𝐹 · 𝐺) ∈ 𝐵) | ||
Theorem | prdsringd 19010 | A product of rings is a ring. (Contributed by Mario Carneiro, 11-Mar-2015.) |
⊢ 𝑌 = (𝑆Xs𝑅) & ⊢ (𝜑 → 𝐼 ∈ 𝑊) & ⊢ (𝜑 → 𝑆 ∈ 𝑉) & ⊢ (𝜑 → 𝑅:𝐼⟶Ring) ⇒ ⊢ (𝜑 → 𝑌 ∈ Ring) | ||
Theorem | prdscrngd 19011 | A product of commutative rings is a commutative ring. Since the resulting ring will have zero divisors in all nontrivial cases, this cannot be strengthened much further. (Contributed by Mario Carneiro, 11-Mar-2015.) |
⊢ 𝑌 = (𝑆Xs𝑅) & ⊢ (𝜑 → 𝐼 ∈ 𝑊) & ⊢ (𝜑 → 𝑆 ∈ 𝑉) & ⊢ (𝜑 → 𝑅:𝐼⟶CRing) ⇒ ⊢ (𝜑 → 𝑌 ∈ CRing) | ||
Theorem | prds1 19012 | Value of the ring unit in a structure family product. (Contributed by Mario Carneiro, 11-Mar-2015.) |
⊢ 𝑌 = (𝑆Xs𝑅) & ⊢ (𝜑 → 𝐼 ∈ 𝑊) & ⊢ (𝜑 → 𝑆 ∈ 𝑉) & ⊢ (𝜑 → 𝑅:𝐼⟶Ring) ⇒ ⊢ (𝜑 → (1r ∘ 𝑅) = (1r‘𝑌)) | ||
Theorem | pwsring 19013 | A structure power of a ring is a ring. (Contributed by Mario Carneiro, 11-Mar-2015.) |
⊢ 𝑌 = (𝑅 ↑s 𝐼) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉) → 𝑌 ∈ Ring) | ||
Theorem | pws1 19014 | Value of the ring unit in a structure power. (Contributed by Mario Carneiro, 11-Mar-2015.) |
⊢ 𝑌 = (𝑅 ↑s 𝐼) & ⊢ 1 = (1r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉) → (𝐼 × { 1 }) = (1r‘𝑌)) | ||
Theorem | pwscrng 19015 | A structure power of a commutative ring is a commutative ring. (Contributed by Mario Carneiro, 11-Mar-2015.) |
⊢ 𝑌 = (𝑅 ↑s 𝐼) ⇒ ⊢ ((𝑅 ∈ CRing ∧ 𝐼 ∈ 𝑉) → 𝑌 ∈ CRing) | ||
Theorem | pwsmgp 19016 | The multiplicative group of the power structure resembles the power of the multiplicative group. (Contributed by Mario Carneiro, 12-Mar-2015.) |
⊢ 𝑌 = (𝑅 ↑s 𝐼) & ⊢ 𝑀 = (mulGrp‘𝑅) & ⊢ 𝑍 = (𝑀 ↑s 𝐼) & ⊢ 𝑁 = (mulGrp‘𝑌) & ⊢ 𝐵 = (Base‘𝑁) & ⊢ 𝐶 = (Base‘𝑍) & ⊢ + = (+g‘𝑁) & ⊢ ✚ = (+g‘𝑍) ⇒ ⊢ ((𝑅 ∈ 𝑉 ∧ 𝐼 ∈ 𝑊) → (𝐵 = 𝐶 ∧ + = ✚ )) | ||
Theorem | imasring 19017* | The image structure of a ring is a ring. (Contributed by Mario Carneiro, 14-Jun-2015.) |
⊢ (𝜑 → 𝑈 = (𝐹 “s 𝑅)) & ⊢ (𝜑 → 𝑉 = (Base‘𝑅)) & ⊢ + = (+g‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 1 = (1r‘𝑅) & ⊢ (𝜑 → 𝐹:𝑉–onto→𝐵) & ⊢ ((𝜑 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) ∧ (𝑝 ∈ 𝑉 ∧ 𝑞 ∈ 𝑉)) → (((𝐹‘𝑎) = (𝐹‘𝑝) ∧ (𝐹‘𝑏) = (𝐹‘𝑞)) → (𝐹‘(𝑎 + 𝑏)) = (𝐹‘(𝑝 + 𝑞)))) & ⊢ ((𝜑 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) ∧ (𝑝 ∈ 𝑉 ∧ 𝑞 ∈ 𝑉)) → (((𝐹‘𝑎) = (𝐹‘𝑝) ∧ (𝐹‘𝑏) = (𝐹‘𝑞)) → (𝐹‘(𝑎 · 𝑏)) = (𝐹‘(𝑝 · 𝑞)))) & ⊢ (𝜑 → 𝑅 ∈ Ring) ⇒ ⊢ (𝜑 → (𝑈 ∈ Ring ∧ (𝐹‘ 1 ) = (1r‘𝑈))) | ||
Theorem | qusring2 19018* | The quotient structure of a ring is a ring. (Contributed by Mario Carneiro, 14-Jun-2015.) |
⊢ (𝜑 → 𝑈 = (𝑅 /s ∼ )) & ⊢ (𝜑 → 𝑉 = (Base‘𝑅)) & ⊢ + = (+g‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 1 = (1r‘𝑅) & ⊢ (𝜑 → ∼ Er 𝑉) & ⊢ (𝜑 → ((𝑎 ∼ 𝑝 ∧ 𝑏 ∼ 𝑞) → (𝑎 + 𝑏) ∼ (𝑝 + 𝑞))) & ⊢ (𝜑 → ((𝑎 ∼ 𝑝 ∧ 𝑏 ∼ 𝑞) → (𝑎 · 𝑏) ∼ (𝑝 · 𝑞))) & ⊢ (𝜑 → 𝑅 ∈ Ring) ⇒ ⊢ (𝜑 → (𝑈 ∈ Ring ∧ [ 1 ] ∼ = (1r‘𝑈))) | ||
Theorem | crngbinom 19019* | The binomial theorem for commutative rings (special case of csrgbinom 18944): (𝐴 + 𝐵)↑𝑁 is the sum from 𝑘 = 0 to 𝑁 of (𝑁C𝑘) · ((𝐴↑𝑘) · (𝐵↑(𝑁 − 𝑘)). (Contributed by AV, 24-Aug-2019.) |
⊢ 𝑆 = (Base‘𝑅) & ⊢ × = (.r‘𝑅) & ⊢ · = (.g‘𝑅) & ⊢ + = (+g‘𝑅) & ⊢ 𝐺 = (mulGrp‘𝑅) & ⊢ ↑ = (.g‘𝐺) ⇒ ⊢ (((𝑅 ∈ CRing ∧ 𝑁 ∈ ℕ0) ∧ (𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆)) → (𝑁 ↑ (𝐴 + 𝐵)) = (𝑅 Σg (𝑘 ∈ (0...𝑁) ↦ ((𝑁C𝑘) · (((𝑁 − 𝑘) ↑ 𝐴) × (𝑘 ↑ 𝐵)))))) | ||
Syntax | coppr 19020 | The opposite ring operation. |
class oppr | ||
Definition | df-oppr 19021 | Define an opposite ring, which is the same as the original ring but with multiplication written the other way around. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ oppr = (𝑓 ∈ V ↦ (𝑓 sSet 〈(.r‘ndx), tpos (.r‘𝑓)〉)) | ||
Theorem | opprval 19022 | Value of the opposite ring. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 𝑂 = (oppr‘𝑅) ⇒ ⊢ 𝑂 = (𝑅 sSet 〈(.r‘ndx), tpos · 〉) | ||
Theorem | opprmulfval 19023 | Value of the multiplication operation of an opposite ring. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 𝑂 = (oppr‘𝑅) & ⊢ ∙ = (.r‘𝑂) ⇒ ⊢ ∙ = tpos · | ||
Theorem | opprmul 19024 | Value of the multiplication operation of an opposite ring. Hypotheses eliminated by a suggestion of Stefan O'Rear, 30-Aug-2015. (Contributed by Mario Carneiro, 1-Dec-2014.) (Revised by Mario Carneiro, 30-Aug-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 𝑂 = (oppr‘𝑅) & ⊢ ∙ = (.r‘𝑂) ⇒ ⊢ (𝑋 ∙ 𝑌) = (𝑌 · 𝑋) | ||
Theorem | crngoppr 19025 | In a commutative ring, the opposite ring is equivalent to the original ring (for theorems like unitpropd 19095). (Contributed by Mario Carneiro, 14-Jun-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 𝑂 = (oppr‘𝑅) & ⊢ ∙ = (.r‘𝑂) ⇒ ⊢ ((𝑅 ∈ CRing ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → (𝑋 · 𝑌) = (𝑋 ∙ 𝑌)) | ||
Theorem | opprlem 19026 | Lemma for opprbas 19027 and oppradd 19028. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝑂 = (oppr‘𝑅) & ⊢ 𝐸 = Slot 𝑁 & ⊢ 𝑁 ∈ ℕ & ⊢ 𝑁 < 3 ⇒ ⊢ (𝐸‘𝑅) = (𝐸‘𝑂) | ||
Theorem | opprbas 19027 | Base set of an opposite ring. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝑂 = (oppr‘𝑅) & ⊢ 𝐵 = (Base‘𝑅) ⇒ ⊢ 𝐵 = (Base‘𝑂) | ||
Theorem | oppradd 19028 | Addition operation of an opposite ring. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝑂 = (oppr‘𝑅) & ⊢ + = (+g‘𝑅) ⇒ ⊢ + = (+g‘𝑂) | ||
Theorem | opprring 19029 | An opposite ring is a ring. (Contributed by Mario Carneiro, 1-Dec-2014.) (Revised by Mario Carneiro, 30-Aug-2015.) |
⊢ 𝑂 = (oppr‘𝑅) ⇒ ⊢ (𝑅 ∈ Ring → 𝑂 ∈ Ring) | ||
Theorem | opprringb 19030 | Bidirectional form of opprring 19029. (Contributed by Mario Carneiro, 6-Dec-2014.) |
⊢ 𝑂 = (oppr‘𝑅) ⇒ ⊢ (𝑅 ∈ Ring ↔ 𝑂 ∈ Ring) | ||
Theorem | oppr0 19031 | Additive identity of an opposite ring. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝑂 = (oppr‘𝑅) & ⊢ 0 = (0g‘𝑅) ⇒ ⊢ 0 = (0g‘𝑂) | ||
Theorem | oppr1 19032 | Multiplicative identity of an opposite ring. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝑂 = (oppr‘𝑅) & ⊢ 1 = (1r‘𝑅) ⇒ ⊢ 1 = (1r‘𝑂) | ||
Theorem | opprneg 19033 | The negative function in an opposite ring. (Contributed by Mario Carneiro, 5-Dec-2014.) (Revised by Mario Carneiro, 2-Oct-2015.) |
⊢ 𝑂 = (oppr‘𝑅) & ⊢ 𝑁 = (invg‘𝑅) ⇒ ⊢ 𝑁 = (invg‘𝑂) | ||
Theorem | opprsubg 19034 | Being a subgroup is a symmetric property. (Contributed by Mario Carneiro, 6-Dec-2014.) |
⊢ 𝑂 = (oppr‘𝑅) ⇒ ⊢ (SubGrp‘𝑅) = (SubGrp‘𝑂) | ||
Theorem | mulgass3 19035 | An associative property between group multiple and ring multiplication. (Contributed by Mario Carneiro, 14-Jun-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ · = (.g‘𝑅) & ⊢ × = (.r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ (𝑁 ∈ ℤ ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵)) → (𝑋 × (𝑁 · 𝑌)) = (𝑁 · (𝑋 × 𝑌))) | ||
Syntax | cdsr 19036 | Ring divisibility relation. |
class ∥r | ||
Syntax | cui 19037 | Ring unit. |
class Unit | ||
Syntax | cir 19038 | Ring irreducibles. |
class Irred | ||
Definition | df-dvdsr 19039* | Define the (right) divisibility relation in a ring. Access to the left divisibility relation is available through (∥r‘(oppr‘𝑅)). (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ ∥r = (𝑤 ∈ V ↦ {〈𝑥, 𝑦〉 ∣ (𝑥 ∈ (Base‘𝑤) ∧ ∃𝑧 ∈ (Base‘𝑤)(𝑧(.r‘𝑤)𝑥) = 𝑦)}) | ||
Definition | df-unit 19040 | Define the set of units in a ring, that is, all elements with a left and right multiplicative inverse. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ Unit = (𝑤 ∈ V ↦ (◡((∥r‘𝑤) ∩ (∥r‘(oppr‘𝑤))) “ {(1r‘𝑤)})) | ||
Definition | df-irred 19041* | Define the set of irreducible elements in a ring. (Contributed by Mario Carneiro, 4-Dec-2014.) |
⊢ Irred = (𝑤 ∈ V ↦ ⦋((Base‘𝑤) ∖ (Unit‘𝑤)) / 𝑏⦌{𝑧 ∈ 𝑏 ∣ ∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥(.r‘𝑤)𝑦) ≠ 𝑧}) | ||
Theorem | reldvdsr 19042 | The divides relation is a relation. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ ∥ = (∥r‘𝑅) ⇒ ⊢ Rel ∥ | ||
Theorem | dvdsrval 19043* | Value of the divides relation. (Contributed by Mario Carneiro, 1-Dec-2014.) (Revised by Mario Carneiro, 6-Jan-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ ∥ = {〈𝑥, 𝑦〉 ∣ (𝑥 ∈ 𝐵 ∧ ∃𝑧 ∈ 𝐵 (𝑧 · 𝑥) = 𝑦)} | ||
Theorem | dvdsr 19044* | Value of the divides relation. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ (𝑋 ∥ 𝑌 ↔ (𝑋 ∈ 𝐵 ∧ ∃𝑧 ∈ 𝐵 (𝑧 · 𝑋) = 𝑌)) | ||
Theorem | dvdsr2 19045* | Value of the divides relation. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ (𝑋 ∈ 𝐵 → (𝑋 ∥ 𝑌 ↔ ∃𝑧 ∈ 𝐵 (𝑧 · 𝑋) = 𝑌)) | ||
Theorem | dvdsrmul 19046 | A left-multiple of 𝑋 is divisible by 𝑋. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → 𝑋 ∥ (𝑌 · 𝑋)) | ||
Theorem | dvdsrcl 19047 | Closure of a dividing element. (Contributed by Mario Carneiro, 5-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) ⇒ ⊢ (𝑋 ∥ 𝑌 → 𝑋 ∈ 𝐵) | ||
Theorem | dvdsrcl2 19048 | Closure of a dividing element. (Contributed by Mario Carneiro, 5-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∥ 𝑌) → 𝑌 ∈ 𝐵) | ||
Theorem | dvdsrid 19049 | An element in a (unital) ring divides itself. (Contributed by Mario Carneiro, 1-Dec-2014.) (Revised by Mario Carneiro, 30-Apr-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝐵) → 𝑋 ∥ 𝑋) | ||
Theorem | dvdsrtr 19050 | Divisibility is transitive. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑌 ∥ 𝑍 ∧ 𝑍 ∥ 𝑋) → 𝑌 ∥ 𝑋) | ||
Theorem | dvdsrmul1 19051 | The divisibility relation is preserved under right-multiplication. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑍 ∈ 𝐵 ∧ 𝑋 ∥ 𝑌) → (𝑋 · 𝑍) ∥ (𝑌 · 𝑍)) | ||
Theorem | dvdsrneg 19052 | An element divides its negative. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) & ⊢ 𝑁 = (invg‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝐵) → 𝑋 ∥ (𝑁‘𝑋)) | ||
Theorem | dvdsr01 19053 | In a ring, zero is divisible by all elements. ("Zero divisor" as a term has a somewhat different meaning, see df-rlreg 19691.) (Contributed by Stefan O'Rear, 29-Mar-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) & ⊢ 0 = (0g‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝐵) → 𝑋 ∥ 0 ) | ||
Theorem | dvdsr02 19054 | Only zero is divisible by zero. (Contributed by Stefan O'Rear, 29-Mar-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ ∥ = (∥r‘𝑅) & ⊢ 0 = (0g‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝐵) → ( 0 ∥ 𝑋 ↔ 𝑋 = 0 )) | ||
Theorem | isunit 19055 | Property of being a unit of a ring. A unit is an element that left- and right-divides one. (Contributed by Mario Carneiro, 1-Dec-2014.) (Revised by Mario Carneiro, 8-Dec-2015.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 1 = (1r‘𝑅) & ⊢ ∥ = (∥r‘𝑅) & ⊢ 𝑆 = (oppr‘𝑅) & ⊢ 𝐸 = (∥r‘𝑆) ⇒ ⊢ (𝑋 ∈ 𝑈 ↔ (𝑋 ∥ 1 ∧ 𝑋𝐸 1 )) | ||
Theorem | 1unit 19056 | The multiplicative identity is a unit. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 1 = (1r‘𝑅) ⇒ ⊢ (𝑅 ∈ Ring → 1 ∈ 𝑈) | ||
Theorem | unitcl 19057 | A unit is an element of the base set. (Contributed by Mario Carneiro, 1-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) ⇒ ⊢ (𝑋 ∈ 𝑈 → 𝑋 ∈ 𝐵) | ||
Theorem | unitss 19058 | The set of units is contained in the base set. (Contributed by Mario Carneiro, 5-Oct-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) ⇒ ⊢ 𝑈 ⊆ 𝐵 | ||
Theorem | opprunit 19059 | Being a unit is a symmetric property, so it transfers to the opposite ring. (Contributed by Mario Carneiro, 4-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝑆 = (oppr‘𝑅) ⇒ ⊢ 𝑈 = (Unit‘𝑆) | ||
Theorem | crngunit 19060 | Property of being a unit in a commutative ring. (Contributed by Mario Carneiro, 18-Apr-2016.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 1 = (1r‘𝑅) & ⊢ ∥ = (∥r‘𝑅) ⇒ ⊢ (𝑅 ∈ CRing → (𝑋 ∈ 𝑈 ↔ 𝑋 ∥ 1 )) | ||
Theorem | dvdsunit 19061 | A divisor of a unit is a unit. (Contributed by Mario Carneiro, 18-Apr-2016.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ ∥ = (∥r‘𝑅) ⇒ ⊢ ((𝑅 ∈ CRing ∧ 𝑌 ∥ 𝑋 ∧ 𝑋 ∈ 𝑈) → 𝑌 ∈ 𝑈) | ||
Theorem | unitmulcl 19062 | The product of units is a unit. (Contributed by Mario Carneiro, 2-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑈) → (𝑋 · 𝑌) ∈ 𝑈) | ||
Theorem | unitmulclb 19063 | Reversal of unitmulcl 19062 in a commutative ring. (Contributed by Mario Carneiro, 18-Apr-2016.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 𝐵 = (Base‘𝑅) ⇒ ⊢ ((𝑅 ∈ CRing ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → ((𝑋 · 𝑌) ∈ 𝑈 ↔ (𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑈))) | ||
Theorem | unitgrpbas 19064 | The base set of the group of units. (Contributed by Mario Carneiro, 25-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐺 = ((mulGrp‘𝑅) ↾s 𝑈) ⇒ ⊢ 𝑈 = (Base‘𝐺) | ||
Theorem | unitgrp 19065 | The group of units is a group under multiplication. (Contributed by Mario Carneiro, 2-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐺 = ((mulGrp‘𝑅) ↾s 𝑈) ⇒ ⊢ (𝑅 ∈ Ring → 𝐺 ∈ Grp) | ||
Theorem | unitabl 19066 | The group of units of a commutative ring is abelian. (Contributed by Mario Carneiro, 19-Apr-2016.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐺 = ((mulGrp‘𝑅) ↾s 𝑈) ⇒ ⊢ (𝑅 ∈ CRing → 𝐺 ∈ Abel) | ||
Theorem | unitgrpid 19067 | The identity of the multiplicative group is 1r. (Contributed by Mario Carneiro, 2-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐺 = ((mulGrp‘𝑅) ↾s 𝑈) & ⊢ 1 = (1r‘𝑅) ⇒ ⊢ (𝑅 ∈ Ring → 1 = (0g‘𝐺)) | ||
Theorem | unitsubm 19068 | The group of units is a submonoid of the multiplicative monoid of the ring. (Contributed by Mario Carneiro, 18-Jun-2015.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝑀 = (mulGrp‘𝑅) ⇒ ⊢ (𝑅 ∈ Ring → 𝑈 ∈ (SubMnd‘𝑀)) | ||
Syntax | cinvr 19069 | Extend class notation with multiplicative inverse. |
class invr | ||
Definition | df-invr 19070 | Define multiplicative inverse. (Contributed by NM, 21-Sep-2011.) |
⊢ invr = (𝑟 ∈ V ↦ (invg‘((mulGrp‘𝑟) ↾s (Unit‘𝑟)))) | ||
Theorem | invrfval 19071 | Multiplicative inverse function for a division ring. (Contributed by NM, 21-Sep-2011.) (Revised by Mario Carneiro, 25-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐺 = ((mulGrp‘𝑅) ↾s 𝑈) & ⊢ 𝐼 = (invr‘𝑅) ⇒ ⊢ 𝐼 = (invg‘𝐺) | ||
Theorem | unitinvcl 19072 | The inverse of a unit exists and is a unit. (Contributed by Mario Carneiro, 2-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐼 = (invr‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝑈) → (𝐼‘𝑋) ∈ 𝑈) | ||
Theorem | unitinvinv 19073 | The inverse of the inverse of a unit is the same element. (Contributed by Mario Carneiro, 4-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐼 = (invr‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝑈) → (𝐼‘(𝐼‘𝑋)) = 𝑋) | ||
Theorem | ringinvcl 19074 | The inverse of a unit is an element of the ring. (Contributed by Mario Carneiro, 2-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐼 = (invr‘𝑅) & ⊢ 𝐵 = (Base‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝑈) → (𝐼‘𝑋) ∈ 𝐵) | ||
Theorem | unitlinv 19075 | A unit times its inverse is the identity. (Contributed by Mario Carneiro, 2-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐼 = (invr‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 1 = (1r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝑈) → ((𝐼‘𝑋) · 𝑋) = 1 ) | ||
Theorem | unitrinv 19076 | A unit times its inverse is the identity. (Contributed by Mario Carneiro, 2-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐼 = (invr‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 1 = (1r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝑈) → (𝑋 · (𝐼‘𝑋)) = 1 ) | ||
Theorem | 1rinv 19077 | The inverse of the identity is the identity. (Contributed by Mario Carneiro, 18-Jun-2015.) |
⊢ 𝐼 = (invr‘𝑅) & ⊢ 1 = (1r‘𝑅) ⇒ ⊢ (𝑅 ∈ Ring → (𝐼‘ 1 ) = 1 ) | ||
Theorem | 0unit 19078 | The additive identity is a unit if and only if 1 = 0, i.e. we are in the zero ring. (Contributed by Mario Carneiro, 4-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 0 = (0g‘𝑅) & ⊢ 1 = (1r‘𝑅) ⇒ ⊢ (𝑅 ∈ Ring → ( 0 ∈ 𝑈 ↔ 1 = 0 )) | ||
Theorem | unitnegcl 19079 | The negative of a unit is a unit. (Contributed by Mario Carneiro, 4-Dec-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝑁 = (invg‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝑈) → (𝑁‘𝑋) ∈ 𝑈) | ||
Syntax | cdvr 19080 | Extend class notation with ring division. |
class /r | ||
Definition | df-dvr 19081* | Define ring division. (Contributed by Mario Carneiro, 2-Jul-2014.) |
⊢ /r = (𝑟 ∈ V ↦ (𝑥 ∈ (Base‘𝑟), 𝑦 ∈ (Unit‘𝑟) ↦ (𝑥(.r‘𝑟)((invr‘𝑟)‘𝑦)))) | ||
Theorem | dvrfval 19082* | Division operation in a ring. (Contributed by Mario Carneiro, 2-Jul-2014.) (Revised by Mario Carneiro, 2-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐼 = (invr‘𝑅) & ⊢ / = (/r‘𝑅) ⇒ ⊢ / = (𝑥 ∈ 𝐵, 𝑦 ∈ 𝑈 ↦ (𝑥 · (𝐼‘𝑦))) | ||
Theorem | dvrval 19083 | Division operation in a ring. (Contributed by Mario Carneiro, 2-Jul-2014.) (Revised by Mario Carneiro, 2-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ · = (.r‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐼 = (invr‘𝑅) & ⊢ / = (/r‘𝑅) ⇒ ⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝑈) → (𝑋 / 𝑌) = (𝑋 · (𝐼‘𝑌))) | ||
Theorem | dvrcl 19084 | Closure of division operation. (Contributed by Mario Carneiro, 2-Jul-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) & ⊢ / = (/r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝑈) → (𝑋 / 𝑌) ∈ 𝐵) | ||
Theorem | unitdvcl 19085 | The units are closed under division. (Contributed by Mario Carneiro, 2-Jul-2014.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ / = (/r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑈) → (𝑋 / 𝑌) ∈ 𝑈) | ||
Theorem | dvrid 19086 | A cancellation law for division. (divid 11065 analog.) (Contributed by Mario Carneiro, 18-Jun-2015.) |
⊢ 𝑈 = (Unit‘𝑅) & ⊢ / = (/r‘𝑅) & ⊢ 1 = (1r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝑈) → (𝑋 / 𝑋) = 1 ) | ||
Theorem | dvr1 19087 | A cancellation law for division. (div1 11067 analog.) (Contributed by Mario Carneiro, 18-Jun-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ / = (/r‘𝑅) & ⊢ 1 = (1r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝐵) → (𝑋 / 1 ) = 𝑋) | ||
Theorem | dvrass 19088 | An associative law for division. (divass 11054 analog.) (Contributed by Mario Carneiro, 4-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) & ⊢ / = (/r‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝑈)) → ((𝑋 · 𝑌) / 𝑍) = (𝑋 · (𝑌 / 𝑍))) | ||
Theorem | dvrcan1 19089 | A cancellation law for division. (divcan1 11045 analog.) (Contributed by Mario Carneiro, 2-Jul-2014.) (Revised by Mario Carneiro, 2-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) & ⊢ / = (/r‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝑈) → ((𝑋 / 𝑌) · 𝑌) = 𝑋) | ||
Theorem | dvrcan3 19090 | A cancellation law for division. (divcan3 11062 analog.) (Contributed by Mario Carneiro, 2-Jul-2014.) (Revised by Mario Carneiro, 18-Jun-2015.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) & ⊢ / = (/r‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝑈) → ((𝑋 · 𝑌) / 𝑌) = 𝑋) | ||
Theorem | dvreq1 19091 | A cancellation law for division. (diveq1 11069 analog.) (Contributed by Mario Carneiro, 28-Apr-2016.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) & ⊢ / = (/r‘𝑅) & ⊢ 1 = (1r‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝑈) → ((𝑋 / 𝑌) = 1 ↔ 𝑋 = 𝑌)) | ||
Theorem | ringinvdv 19092 | Write the inverse function in terms of division. (Contributed by Mario Carneiro, 2-Jul-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) & ⊢ / = (/r‘𝑅) & ⊢ 1 = (1r‘𝑅) & ⊢ 𝐼 = (invr‘𝑅) ⇒ ⊢ ((𝑅 ∈ Ring ∧ 𝑋 ∈ 𝑈) → (𝐼‘𝑋) = ( 1 / 𝑋)) | ||
Theorem | rngidpropd 19093* | The ring identity depends only on the ring's base set and multiplication operation. (Contributed by Mario Carneiro, 26-Dec-2014.) |
⊢ (𝜑 → 𝐵 = (Base‘𝐾)) & ⊢ (𝜑 → 𝐵 = (Base‘𝐿)) & ⊢ ((𝜑 ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → (𝑥(.r‘𝐾)𝑦) = (𝑥(.r‘𝐿)𝑦)) ⇒ ⊢ (𝜑 → (1r‘𝐾) = (1r‘𝐿)) | ||
Theorem | dvdsrpropd 19094* | The divisibility relation depends only on the ring's base set and multiplication operation. (Contributed by Mario Carneiro, 26-Dec-2014.) |
⊢ (𝜑 → 𝐵 = (Base‘𝐾)) & ⊢ (𝜑 → 𝐵 = (Base‘𝐿)) & ⊢ ((𝜑 ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → (𝑥(.r‘𝐾)𝑦) = (𝑥(.r‘𝐿)𝑦)) ⇒ ⊢ (𝜑 → (∥r‘𝐾) = (∥r‘𝐿)) | ||
Theorem | unitpropd 19095* | The set of units depends only on the ring's base set and multiplication operation. (Contributed by Mario Carneiro, 26-Dec-2014.) |
⊢ (𝜑 → 𝐵 = (Base‘𝐾)) & ⊢ (𝜑 → 𝐵 = (Base‘𝐿)) & ⊢ ((𝜑 ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → (𝑥(.r‘𝐾)𝑦) = (𝑥(.r‘𝐿)𝑦)) ⇒ ⊢ (𝜑 → (Unit‘𝐾) = (Unit‘𝐿)) | ||
Theorem | invrpropd 19096* | The ring inverse function depends only on the ring's base set and multiplication operation. (Contributed by Mario Carneiro, 26-Dec-2014.) (Revised by Mario Carneiro, 5-Oct-2015.) |
⊢ (𝜑 → 𝐵 = (Base‘𝐾)) & ⊢ (𝜑 → 𝐵 = (Base‘𝐿)) & ⊢ ((𝜑 ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → (𝑥(.r‘𝐾)𝑦) = (𝑥(.r‘𝐿)𝑦)) ⇒ ⊢ (𝜑 → (invr‘𝐾) = (invr‘𝐿)) | ||
Theorem | isirred 19097* | An irreducible element of a ring is a non-unit that is not the product of two non-units. (Contributed by Mario Carneiro, 4-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐼 = (Irred‘𝑅) & ⊢ 𝑁 = (𝐵 ∖ 𝑈) & ⊢ · = (.r‘𝑅) ⇒ ⊢ (𝑋 ∈ 𝐼 ↔ (𝑋 ∈ 𝑁 ∧ ∀𝑥 ∈ 𝑁 ∀𝑦 ∈ 𝑁 (𝑥 · 𝑦) ≠ 𝑋)) | ||
Theorem | isnirred 19098* | The property of being a non-irreducible (reducible) element in a ring. (Contributed by Mario Carneiro, 4-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐼 = (Irred‘𝑅) & ⊢ 𝑁 = (𝐵 ∖ 𝑈) & ⊢ · = (.r‘𝑅) ⇒ ⊢ (𝑋 ∈ 𝐵 → (¬ 𝑋 ∈ 𝐼 ↔ (𝑋 ∈ 𝑈 ∨ ∃𝑥 ∈ 𝑁 ∃𝑦 ∈ 𝑁 (𝑥 · 𝑦) = 𝑋))) | ||
Theorem | isirred2 19099* | Expand out the class difference from isirred 19097. (Contributed by Mario Carneiro, 4-Dec-2014.) |
⊢ 𝐵 = (Base‘𝑅) & ⊢ 𝑈 = (Unit‘𝑅) & ⊢ 𝐼 = (Irred‘𝑅) & ⊢ · = (.r‘𝑅) ⇒ ⊢ (𝑋 ∈ 𝐼 ↔ (𝑋 ∈ 𝐵 ∧ ¬ 𝑋 ∈ 𝑈 ∧ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ((𝑥 · 𝑦) = 𝑋 → (𝑥 ∈ 𝑈 ∨ 𝑦 ∈ 𝑈)))) | ||
Theorem | opprirred 19100 | Irreducibility is symmetric, so the irreducible elements of the opposite ring are the same as the original ring. (Contributed by Mario Carneiro, 4-Dec-2014.) |
⊢ 𝑆 = (oppr‘𝑅) & ⊢ 𝐼 = (Irred‘𝑅) ⇒ ⊢ 𝐼 = (Irred‘𝑆) |
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