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| Type | Label | Description |
|---|---|---|
| Statement | ||
| Theorem | qseq1 8801 | Equality theorem for quotient set. (Contributed by NM, 23-Jul-1995.) |
| ⊢ (𝐴 = 𝐵 → (𝐴 / 𝐶) = (𝐵 / 𝐶)) | ||
| Theorem | qseq2 8802 | Equality theorem for quotient set. (Contributed by NM, 23-Jul-1995.) |
| ⊢ (𝐴 = 𝐵 → (𝐶 / 𝐴) = (𝐶 / 𝐵)) | ||
| Theorem | qseq2i 8803 | Equality theorem for quotient set, inference form. (Contributed by Peter Mazsa, 3-Jun-2021.) |
| ⊢ 𝐴 = 𝐵 ⇒ ⊢ (𝐶 / 𝐴) = (𝐶 / 𝐵) | ||
| Theorem | qseq1d 8804 | Equality theorem for quotient set, deduction form. (Contributed by Peter Mazsa, 27-May-2021.) |
| ⊢ (𝜑 → 𝐴 = 𝐵) ⇒ ⊢ (𝜑 → (𝐴 / 𝐶) = (𝐵 / 𝐶)) | ||
| Theorem | qseq2d 8805 | Equality theorem for quotient set, deduction form. (Contributed by Peter Mazsa, 27-May-2021.) |
| ⊢ (𝜑 → 𝐴 = 𝐵) ⇒ ⊢ (𝜑 → (𝐶 / 𝐴) = (𝐶 / 𝐵)) | ||
| Theorem | qseq12 8806 | Equality theorem for quotient set. (Contributed by Peter Mazsa, 17-Apr-2019.) |
| ⊢ ((𝐴 = 𝐵 ∧ 𝐶 = 𝐷) → (𝐴 / 𝐶) = (𝐵 / 𝐷)) | ||
| Theorem | 0qs 8807 | Quotient set with the empty set. (Contributed by Peter Mazsa, 14-Sep-2019.) |
| ⊢ (∅ / 𝑅) = ∅ | ||
| Theorem | elqsg 8808* | Closed form of elqs 8809. (Contributed by Rodolfo Medina, 12-Oct-2010.) |
| ⊢ (𝐵 ∈ 𝑉 → (𝐵 ∈ (𝐴 / 𝑅) ↔ ∃𝑥 ∈ 𝐴 𝐵 = [𝑥]𝑅)) | ||
| Theorem | elqs 8809* | Membership in a quotient set. (Contributed by NM, 23-Jul-1995.) |
| ⊢ 𝐵 ∈ V ⇒ ⊢ (𝐵 ∈ (𝐴 / 𝑅) ↔ ∃𝑥 ∈ 𝐴 𝐵 = [𝑥]𝑅) | ||
| Theorem | elqsi 8810* | Membership in a quotient set. (Contributed by NM, 23-Jul-1995.) |
| ⊢ (𝐵 ∈ (𝐴 / 𝑅) → ∃𝑥 ∈ 𝐴 𝐵 = [𝑥]𝑅) | ||
| Theorem | elqsecl 8811* | Membership in a quotient set by an equivalence class according to ∼. (Contributed by Alexander van der Vekens, 12-Apr-2018.) (Revised by AV, 30-Apr-2021.) |
| ⊢ (𝐵 ∈ 𝑋 → (𝐵 ∈ (𝑊 / ∼ ) ↔ ∃𝑥 ∈ 𝑊 𝐵 = {𝑦 ∣ 𝑥 ∼ 𝑦})) | ||
| Theorem | ecelqsg 8812 | Membership of an equivalence class in a quotient set. (Contributed by Jeff Madsen, 10-Jun-2010.) (Revised by Mario Carneiro, 9-Jul-2014.) |
| ⊢ ((𝑅 ∈ 𝑉 ∧ 𝐵 ∈ 𝐴) → [𝐵]𝑅 ∈ (𝐴 / 𝑅)) | ||
| Theorem | ecelqsi 8813 | Membership of an equivalence class in a quotient set. (Contributed by NM, 25-Jul-1995.) (Revised by Mario Carneiro, 9-Jul-2014.) |
| ⊢ 𝑅 ∈ V ⇒ ⊢ (𝐵 ∈ 𝐴 → [𝐵]𝑅 ∈ (𝐴 / 𝑅)) | ||
| Theorem | ecopqsi 8814 | "Closure" law for equivalence class of ordered pairs. (Contributed by NM, 25-Mar-1996.) |
| ⊢ 𝑅 ∈ V & ⊢ 𝑆 = ((𝐴 × 𝐴) / 𝑅) ⇒ ⊢ ((𝐵 ∈ 𝐴 ∧ 𝐶 ∈ 𝐴) → [〈𝐵, 𝐶〉]𝑅 ∈ 𝑆) | ||
| Theorem | qsexg 8815 | A quotient set exists. (Contributed by FL, 19-May-2007.) (Revised by Mario Carneiro, 9-Jul-2014.) |
| ⊢ (𝐴 ∈ 𝑉 → (𝐴 / 𝑅) ∈ V) | ||
| Theorem | qsex 8816 | A quotient set exists. (Contributed by NM, 14-Aug-1995.) |
| ⊢ 𝐴 ∈ V ⇒ ⊢ (𝐴 / 𝑅) ∈ V | ||
| Theorem | uniqs 8817 | The union of a quotient set. (Contributed by NM, 9-Dec-2008.) |
| ⊢ (𝑅 ∈ 𝑉 → ∪ (𝐴 / 𝑅) = (𝑅 “ 𝐴)) | ||
| Theorem | qsss 8818 | A quotient set is a set of subsets of the base set. (Contributed by Mario Carneiro, 9-Jul-2014.) (Revised by Mario Carneiro, 12-Aug-2015.) |
| ⊢ (𝜑 → 𝑅 Er 𝐴) ⇒ ⊢ (𝜑 → (𝐴 / 𝑅) ⊆ 𝒫 𝐴) | ||
| Theorem | uniqs2 8819 | The union of a quotient set. (Contributed by Mario Carneiro, 11-Jul-2014.) |
| ⊢ (𝜑 → 𝑅 Er 𝐴) & ⊢ (𝜑 → 𝑅 ∈ 𝑉) ⇒ ⊢ (𝜑 → ∪ (𝐴 / 𝑅) = 𝐴) | ||
| Theorem | snec 8820 | The singleton of an equivalence class. (Contributed by NM, 29-Jan-1999.) (Revised by Mario Carneiro, 9-Jul-2014.) |
| ⊢ 𝐴 ∈ V ⇒ ⊢ {[𝐴]𝑅} = ({𝐴} / 𝑅) | ||
| Theorem | ecqs 8821 | Equivalence class in terms of quotient set. (Contributed by NM, 29-Jan-1999.) |
| ⊢ 𝑅 ∈ V ⇒ ⊢ [𝐴]𝑅 = ∪ ({𝐴} / 𝑅) | ||
| Theorem | ecid 8822 | A set is equal to its coset under the converse membership relation. (Note: the converse membership relation is not an equivalence relation.) (Contributed by NM, 13-Aug-1995.) (Revised by Mario Carneiro, 9-Jul-2014.) |
| ⊢ 𝐴 ∈ V ⇒ ⊢ [𝐴]◡ E = 𝐴 | ||
| Theorem | qsid 8823 | A set is equal to its quotient set modulo the converse membership relation. (Note: the converse membership relation is not an equivalence relation.) (Contributed by NM, 13-Aug-1995.) (Revised by Mario Carneiro, 9-Jul-2014.) |
| ⊢ (𝐴 / ◡ E ) = 𝐴 | ||
| Theorem | ectocld 8824* | Implicit substitution of class for equivalence class. (Contributed by Mario Carneiro, 9-Jul-2014.) |
| ⊢ 𝑆 = (𝐵 / 𝑅) & ⊢ ([𝑥]𝑅 = 𝐴 → (𝜑 ↔ 𝜓)) & ⊢ ((𝜒 ∧ 𝑥 ∈ 𝐵) → 𝜑) ⇒ ⊢ ((𝜒 ∧ 𝐴 ∈ 𝑆) → 𝜓) | ||
| Theorem | ectocl 8825* | Implicit substitution of class for equivalence class. (Contributed by NM, 23-Jul-1995.) (Revised by Mario Carneiro, 9-Jul-2014.) |
| ⊢ 𝑆 = (𝐵 / 𝑅) & ⊢ ([𝑥]𝑅 = 𝐴 → (𝜑 ↔ 𝜓)) & ⊢ (𝑥 ∈ 𝐵 → 𝜑) ⇒ ⊢ (𝐴 ∈ 𝑆 → 𝜓) | ||
| Theorem | elqsn0 8826 | A quotient set does not contain the empty set. (Contributed by NM, 24-Aug-1995.) |
| ⊢ ((dom 𝑅 = 𝐴 ∧ 𝐵 ∈ (𝐴 / 𝑅)) → 𝐵 ≠ ∅) | ||
| Theorem | ecelqsdm 8827 | Membership of an equivalence class in a quotient set. (Contributed by NM, 30-Jul-1995.) |
| ⊢ ((dom 𝑅 = 𝐴 ∧ [𝐵]𝑅 ∈ (𝐴 / 𝑅)) → 𝐵 ∈ 𝐴) | ||
| Theorem | xpider 8828 | A Cartesian square is an equivalence relation (in general, it is not a poset). (Contributed by FL, 31-Jul-2009.) (Revised by Mario Carneiro, 12-Aug-2015.) |
| ⊢ (𝐴 × 𝐴) Er 𝐴 | ||
| Theorem | iiner 8829* | The intersection of a nonempty family of equivalence relations is an equivalence relation. (Contributed by Mario Carneiro, 27-Sep-2015.) |
| ⊢ ((𝐴 ≠ ∅ ∧ ∀𝑥 ∈ 𝐴 𝑅 Er 𝐵) → ∩ 𝑥 ∈ 𝐴 𝑅 Er 𝐵) | ||
| Theorem | riiner 8830* | The relative intersection of a family of equivalence relations is an equivalence relation. (Contributed by Mario Carneiro, 27-Sep-2015.) |
| ⊢ (∀𝑥 ∈ 𝐴 𝑅 Er 𝐵 → ((𝐵 × 𝐵) ∩ ∩ 𝑥 ∈ 𝐴 𝑅) Er 𝐵) | ||
| Theorem | erinxp 8831 | A restricted equivalence relation is an equivalence relation. (Contributed by Mario Carneiro, 10-Jul-2015.) (Revised by Mario Carneiro, 12-Aug-2015.) |
| ⊢ (𝜑 → 𝑅 Er 𝐴) & ⊢ (𝜑 → 𝐵 ⊆ 𝐴) ⇒ ⊢ (𝜑 → (𝑅 ∩ (𝐵 × 𝐵)) Er 𝐵) | ||
| Theorem | ecinxp 8832 | Restrict the relation in an equivalence class to a base set. (Contributed by Mario Carneiro, 10-Jul-2015.) |
| ⊢ (((𝑅 “ 𝐴) ⊆ 𝐴 ∧ 𝐵 ∈ 𝐴) → [𝐵]𝑅 = [𝐵](𝑅 ∩ (𝐴 × 𝐴))) | ||
| Theorem | qsinxp 8833 | Restrict the equivalence relation in a quotient set to the base set. (Contributed by Mario Carneiro, 23-Feb-2015.) |
| ⊢ ((𝑅 “ 𝐴) ⊆ 𝐴 → (𝐴 / 𝑅) = (𝐴 / (𝑅 ∩ (𝐴 × 𝐴)))) | ||
| Theorem | qsdisj 8834 | Members of a quotient set do not overlap. (Contributed by Rodolfo Medina, 12-Oct-2010.) (Revised by Mario Carneiro, 11-Jul-2014.) |
| ⊢ (𝜑 → 𝑅 Er 𝑋) & ⊢ (𝜑 → 𝐵 ∈ (𝐴 / 𝑅)) & ⊢ (𝜑 → 𝐶 ∈ (𝐴 / 𝑅)) ⇒ ⊢ (𝜑 → (𝐵 = 𝐶 ∨ (𝐵 ∩ 𝐶) = ∅)) | ||
| Theorem | qsdisj2 8835* | A quotient set is a disjoint set. (Contributed by Mario Carneiro, 10-Dec-2016.) |
| ⊢ (𝑅 Er 𝑋 → Disj 𝑥 ∈ (𝐴 / 𝑅)𝑥) | ||
| Theorem | qsel 8836 | If an element of a quotient set contains a given element, it is equal to the equivalence class of the element. (Contributed by Mario Carneiro, 12-Aug-2015.) |
| ⊢ ((𝑅 Er 𝑋 ∧ 𝐵 ∈ (𝐴 / 𝑅) ∧ 𝐶 ∈ 𝐵) → 𝐵 = [𝐶]𝑅) | ||
| Theorem | uniinqs 8837 | Class union distributes over the intersection of two subclasses of a quotient space. Compare uniin 4931. (Contributed by FL, 25-May-2007.) (Proof shortened by Mario Carneiro, 11-Jul-2014.) |
| ⊢ 𝑅 Er 𝑋 ⇒ ⊢ ((𝐵 ⊆ (𝐴 / 𝑅) ∧ 𝐶 ⊆ (𝐴 / 𝑅)) → ∪ (𝐵 ∩ 𝐶) = (∪ 𝐵 ∩ ∪ 𝐶)) | ||
| Theorem | qliftlem 8838* | Lemma for theorems about a function lift. (Contributed by Mario Carneiro, 23-Dec-2016.) (Revised by AV, 3-Aug-2024.) |
| ⊢ 𝐹 = ran (𝑥 ∈ 𝑋 ↦ 〈[𝑥]𝑅, 𝐴〉) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑋) → 𝐴 ∈ 𝑌) & ⊢ (𝜑 → 𝑅 Er 𝑋) & ⊢ (𝜑 → 𝑋 ∈ 𝑉) ⇒ ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑋) → [𝑥]𝑅 ∈ (𝑋 / 𝑅)) | ||
| Theorem | qliftrel 8839* | 𝐹, a function lift, is a subset of 𝑅 × 𝑆. (Contributed by Mario Carneiro, 23-Dec-2016.) (Revised by AV, 3-Aug-2024.) |
| ⊢ 𝐹 = ran (𝑥 ∈ 𝑋 ↦ 〈[𝑥]𝑅, 𝐴〉) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑋) → 𝐴 ∈ 𝑌) & ⊢ (𝜑 → 𝑅 Er 𝑋) & ⊢ (𝜑 → 𝑋 ∈ 𝑉) ⇒ ⊢ (𝜑 → 𝐹 ⊆ ((𝑋 / 𝑅) × 𝑌)) | ||
| Theorem | qliftel 8840* | Elementhood in the relation 𝐹. (Contributed by Mario Carneiro, 23-Dec-2016.) (Revised by AV, 3-Aug-2024.) |
| ⊢ 𝐹 = ran (𝑥 ∈ 𝑋 ↦ 〈[𝑥]𝑅, 𝐴〉) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑋) → 𝐴 ∈ 𝑌) & ⊢ (𝜑 → 𝑅 Er 𝑋) & ⊢ (𝜑 → 𝑋 ∈ 𝑉) ⇒ ⊢ (𝜑 → ([𝐶]𝑅𝐹𝐷 ↔ ∃𝑥 ∈ 𝑋 (𝐶𝑅𝑥 ∧ 𝐷 = 𝐴))) | ||
| Theorem | qliftel1 8841* | Elementhood in the relation 𝐹. (Contributed by Mario Carneiro, 23-Dec-2016.) (Revised by AV, 3-Aug-2024.) |
| ⊢ 𝐹 = ran (𝑥 ∈ 𝑋 ↦ 〈[𝑥]𝑅, 𝐴〉) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑋) → 𝐴 ∈ 𝑌) & ⊢ (𝜑 → 𝑅 Er 𝑋) & ⊢ (𝜑 → 𝑋 ∈ 𝑉) ⇒ ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑋) → [𝑥]𝑅𝐹𝐴) | ||
| Theorem | qliftfun 8842* | The function 𝐹 is the unique function defined by 𝐹‘[𝑥] = 𝐴, provided that the well-definedness condition holds. (Contributed by Mario Carneiro, 23-Dec-2016.) (Revised by AV, 3-Aug-2024.) |
| ⊢ 𝐹 = ran (𝑥 ∈ 𝑋 ↦ 〈[𝑥]𝑅, 𝐴〉) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑋) → 𝐴 ∈ 𝑌) & ⊢ (𝜑 → 𝑅 Er 𝑋) & ⊢ (𝜑 → 𝑋 ∈ 𝑉) & ⊢ (𝑥 = 𝑦 → 𝐴 = 𝐵) ⇒ ⊢ (𝜑 → (Fun 𝐹 ↔ ∀𝑥∀𝑦(𝑥𝑅𝑦 → 𝐴 = 𝐵))) | ||
| Theorem | qliftfund 8843* | The function 𝐹 is the unique function defined by 𝐹‘[𝑥] = 𝐴, provided that the well-definedness condition holds. (Contributed by Mario Carneiro, 23-Dec-2016.) (Revised by AV, 3-Aug-2024.) |
| ⊢ 𝐹 = ran (𝑥 ∈ 𝑋 ↦ 〈[𝑥]𝑅, 𝐴〉) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑋) → 𝐴 ∈ 𝑌) & ⊢ (𝜑 → 𝑅 Er 𝑋) & ⊢ (𝜑 → 𝑋 ∈ 𝑉) & ⊢ (𝑥 = 𝑦 → 𝐴 = 𝐵) & ⊢ ((𝜑 ∧ 𝑥𝑅𝑦) → 𝐴 = 𝐵) ⇒ ⊢ (𝜑 → Fun 𝐹) | ||
| Theorem | qliftfuns 8844* | The function 𝐹 is the unique function defined by 𝐹‘[𝑥] = 𝐴, provided that the well-definedness condition holds. (Contributed by Mario Carneiro, 23-Dec-2016.) (Revised by AV, 3-Aug-2024.) |
| ⊢ 𝐹 = ran (𝑥 ∈ 𝑋 ↦ 〈[𝑥]𝑅, 𝐴〉) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑋) → 𝐴 ∈ 𝑌) & ⊢ (𝜑 → 𝑅 Er 𝑋) & ⊢ (𝜑 → 𝑋 ∈ 𝑉) ⇒ ⊢ (𝜑 → (Fun 𝐹 ↔ ∀𝑦∀𝑧(𝑦𝑅𝑧 → ⦋𝑦 / 𝑥⦌𝐴 = ⦋𝑧 / 𝑥⦌𝐴))) | ||
| Theorem | qliftf 8845* | The domain and codomain of the function 𝐹. (Contributed by Mario Carneiro, 23-Dec-2016.) (Revised by AV, 3-Aug-2024.) |
| ⊢ 𝐹 = ran (𝑥 ∈ 𝑋 ↦ 〈[𝑥]𝑅, 𝐴〉) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑋) → 𝐴 ∈ 𝑌) & ⊢ (𝜑 → 𝑅 Er 𝑋) & ⊢ (𝜑 → 𝑋 ∈ 𝑉) ⇒ ⊢ (𝜑 → (Fun 𝐹 ↔ 𝐹:(𝑋 / 𝑅)⟶𝑌)) | ||
| Theorem | qliftval 8846* | The value of the function 𝐹. (Contributed by Mario Carneiro, 23-Dec-2016.) (Revised by AV, 3-Aug-2024.) |
| ⊢ 𝐹 = ran (𝑥 ∈ 𝑋 ↦ 〈[𝑥]𝑅, 𝐴〉) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑋) → 𝐴 ∈ 𝑌) & ⊢ (𝜑 → 𝑅 Er 𝑋) & ⊢ (𝜑 → 𝑋 ∈ 𝑉) & ⊢ (𝑥 = 𝐶 → 𝐴 = 𝐵) & ⊢ (𝜑 → Fun 𝐹) ⇒ ⊢ ((𝜑 ∧ 𝐶 ∈ 𝑋) → (𝐹‘[𝐶]𝑅) = 𝐵) | ||
| Theorem | ecoptocl 8847* | Implicit substitution of class for equivalence class of ordered pair. (Contributed by NM, 23-Jul-1995.) |
| ⊢ 𝑆 = ((𝐵 × 𝐶) / 𝑅) & ⊢ ([〈𝑥, 𝑦〉]𝑅 = 𝐴 → (𝜑 ↔ 𝜓)) & ⊢ ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶) → 𝜑) ⇒ ⊢ (𝐴 ∈ 𝑆 → 𝜓) | ||
| Theorem | 2ecoptocl 8848* | Implicit substitution of classes for equivalence classes of ordered pairs. (Contributed by NM, 23-Jul-1995.) |
| ⊢ 𝑆 = ((𝐶 × 𝐷) / 𝑅) & ⊢ ([〈𝑥, 𝑦〉]𝑅 = 𝐴 → (𝜑 ↔ 𝜓)) & ⊢ ([〈𝑧, 𝑤〉]𝑅 = 𝐵 → (𝜓 ↔ 𝜒)) & ⊢ (((𝑥 ∈ 𝐶 ∧ 𝑦 ∈ 𝐷) ∧ (𝑧 ∈ 𝐶 ∧ 𝑤 ∈ 𝐷)) → 𝜑) ⇒ ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆) → 𝜒) | ||
| Theorem | 3ecoptocl 8849* | Implicit substitution of classes for equivalence classes of ordered pairs. (Contributed by NM, 9-Aug-1995.) |
| ⊢ 𝑆 = ((𝐷 × 𝐷) / 𝑅) & ⊢ ([〈𝑥, 𝑦〉]𝑅 = 𝐴 → (𝜑 ↔ 𝜓)) & ⊢ ([〈𝑧, 𝑤〉]𝑅 = 𝐵 → (𝜓 ↔ 𝜒)) & ⊢ ([〈𝑣, 𝑢〉]𝑅 = 𝐶 → (𝜒 ↔ 𝜃)) & ⊢ (((𝑥 ∈ 𝐷 ∧ 𝑦 ∈ 𝐷) ∧ (𝑧 ∈ 𝐷 ∧ 𝑤 ∈ 𝐷) ∧ (𝑣 ∈ 𝐷 ∧ 𝑢 ∈ 𝐷)) → 𝜑) ⇒ ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆 ∧ 𝐶 ∈ 𝑆) → 𝜃) | ||
| Theorem | brecop 8850* | Binary relation on a quotient set. Lemma for real number construction. (Contributed by NM, 29-Jan-1996.) |
| ⊢ ∼ ∈ V & ⊢ ∼ Er (𝐺 × 𝐺) & ⊢ 𝐻 = ((𝐺 × 𝐺) / ∼ ) & ⊢ ≤ = {〈𝑥, 𝑦〉 ∣ ((𝑥 ∈ 𝐻 ∧ 𝑦 ∈ 𝐻) ∧ ∃𝑧∃𝑤∃𝑣∃𝑢((𝑥 = [〈𝑧, 𝑤〉] ∼ ∧ 𝑦 = [〈𝑣, 𝑢〉] ∼ ) ∧ 𝜑))} & ⊢ ((((𝑧 ∈ 𝐺 ∧ 𝑤 ∈ 𝐺) ∧ (𝐴 ∈ 𝐺 ∧ 𝐵 ∈ 𝐺)) ∧ ((𝑣 ∈ 𝐺 ∧ 𝑢 ∈ 𝐺) ∧ (𝐶 ∈ 𝐺 ∧ 𝐷 ∈ 𝐺))) → (([〈𝑧, 𝑤〉] ∼ = [〈𝐴, 𝐵〉] ∼ ∧ [〈𝑣, 𝑢〉] ∼ = [〈𝐶, 𝐷〉] ∼ ) → (𝜑 ↔ 𝜓))) ⇒ ⊢ (((𝐴 ∈ 𝐺 ∧ 𝐵 ∈ 𝐺) ∧ (𝐶 ∈ 𝐺 ∧ 𝐷 ∈ 𝐺)) → ([〈𝐴, 𝐵〉] ∼ ≤ [〈𝐶, 𝐷〉] ∼ ↔ 𝜓)) | ||
| Theorem | brecop2 8851 | Binary relation on a quotient set. Lemma for real number construction. Eliminates antecedent from last hypothesis. (Contributed by NM, 13-Feb-1996.) (Revised by AV, 12-Jul-2022.) |
| ⊢ dom ∼ = (𝐺 × 𝐺) & ⊢ 𝐻 = ((𝐺 × 𝐺) / ∼ ) & ⊢ 𝑅 ⊆ (𝐻 × 𝐻) & ⊢ ≤ ⊆ (𝐺 × 𝐺) & ⊢ ¬ ∅ ∈ 𝐺 & ⊢ dom + = (𝐺 × 𝐺) & ⊢ (((𝐴 ∈ 𝐺 ∧ 𝐵 ∈ 𝐺) ∧ (𝐶 ∈ 𝐺 ∧ 𝐷 ∈ 𝐺)) → ([〈𝐴, 𝐵〉] ∼ 𝑅[〈𝐶, 𝐷〉] ∼ ↔ (𝐴 + 𝐷) ≤ (𝐵 + 𝐶))) ⇒ ⊢ ([〈𝐴, 𝐵〉] ∼ 𝑅[〈𝐶, 𝐷〉] ∼ ↔ (𝐴 + 𝐷) ≤ (𝐵 + 𝐶)) | ||
| Theorem | eroveu 8852* | Lemma for erov 8854 and eroprf 8855. (Contributed by Jeff Madsen, 10-Jun-2010.) (Revised by Mario Carneiro, 9-Jul-2014.) |
| ⊢ 𝐽 = (𝐴 / 𝑅) & ⊢ 𝐾 = (𝐵 / 𝑆) & ⊢ (𝜑 → 𝑇 ∈ 𝑍) & ⊢ (𝜑 → 𝑅 Er 𝑈) & ⊢ (𝜑 → 𝑆 Er 𝑉) & ⊢ (𝜑 → 𝑇 Er 𝑊) & ⊢ (𝜑 → 𝐴 ⊆ 𝑈) & ⊢ (𝜑 → 𝐵 ⊆ 𝑉) & ⊢ (𝜑 → 𝐶 ⊆ 𝑊) & ⊢ (𝜑 → + :(𝐴 × 𝐵)⟶𝐶) & ⊢ ((𝜑 ∧ ((𝑟 ∈ 𝐴 ∧ 𝑠 ∈ 𝐴) ∧ (𝑡 ∈ 𝐵 ∧ 𝑢 ∈ 𝐵))) → ((𝑟𝑅𝑠 ∧ 𝑡𝑆𝑢) → (𝑟 + 𝑡)𝑇(𝑠 + 𝑢))) ⇒ ⊢ ((𝜑 ∧ (𝑋 ∈ 𝐽 ∧ 𝑌 ∈ 𝐾)) → ∃!𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 ((𝑋 = [𝑝]𝑅 ∧ 𝑌 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)) | ||
| Theorem | erovlem 8853* | Lemma for erov 8854 and eroprf 8855. (Contributed by Jeff Madsen, 10-Jun-2010.) (Revised by Mario Carneiro, 30-Dec-2014.) |
| ⊢ 𝐽 = (𝐴 / 𝑅) & ⊢ 𝐾 = (𝐵 / 𝑆) & ⊢ (𝜑 → 𝑇 ∈ 𝑍) & ⊢ (𝜑 → 𝑅 Er 𝑈) & ⊢ (𝜑 → 𝑆 Er 𝑉) & ⊢ (𝜑 → 𝑇 Er 𝑊) & ⊢ (𝜑 → 𝐴 ⊆ 𝑈) & ⊢ (𝜑 → 𝐵 ⊆ 𝑉) & ⊢ (𝜑 → 𝐶 ⊆ 𝑊) & ⊢ (𝜑 → + :(𝐴 × 𝐵)⟶𝐶) & ⊢ ((𝜑 ∧ ((𝑟 ∈ 𝐴 ∧ 𝑠 ∈ 𝐴) ∧ (𝑡 ∈ 𝐵 ∧ 𝑢 ∈ 𝐵))) → ((𝑟𝑅𝑠 ∧ 𝑡𝑆𝑢) → (𝑟 + 𝑡)𝑇(𝑠 + 𝑢))) & ⊢ ⨣ = {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 ((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)} ⇒ ⊢ (𝜑 → ⨣ = (𝑥 ∈ 𝐽, 𝑦 ∈ 𝐾 ↦ (℩𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 ((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)))) | ||
| Theorem | erov 8854* | The value of an operation defined on equivalence classes. (Contributed by Jeff Madsen, 10-Jun-2010.) (Revised by Mario Carneiro, 30-Dec-2014.) |
| ⊢ 𝐽 = (𝐴 / 𝑅) & ⊢ 𝐾 = (𝐵 / 𝑆) & ⊢ (𝜑 → 𝑇 ∈ 𝑍) & ⊢ (𝜑 → 𝑅 Er 𝑈) & ⊢ (𝜑 → 𝑆 Er 𝑉) & ⊢ (𝜑 → 𝑇 Er 𝑊) & ⊢ (𝜑 → 𝐴 ⊆ 𝑈) & ⊢ (𝜑 → 𝐵 ⊆ 𝑉) & ⊢ (𝜑 → 𝐶 ⊆ 𝑊) & ⊢ (𝜑 → + :(𝐴 × 𝐵)⟶𝐶) & ⊢ ((𝜑 ∧ ((𝑟 ∈ 𝐴 ∧ 𝑠 ∈ 𝐴) ∧ (𝑡 ∈ 𝐵 ∧ 𝑢 ∈ 𝐵))) → ((𝑟𝑅𝑠 ∧ 𝑡𝑆𝑢) → (𝑟 + 𝑡)𝑇(𝑠 + 𝑢))) & ⊢ ⨣ = {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 ((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)} & ⊢ (𝜑 → 𝑅 ∈ 𝑋) & ⊢ (𝜑 → 𝑆 ∈ 𝑌) ⇒ ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → ([𝑃]𝑅 ⨣ [𝑄]𝑆) = [(𝑃 + 𝑄)]𝑇) | ||
| Theorem | eroprf 8855* | Functionality of an operation defined on equivalence classes. (Contributed by Jeff Madsen, 10-Jun-2010.) (Revised by Mario Carneiro, 30-Dec-2014.) |
| ⊢ 𝐽 = (𝐴 / 𝑅) & ⊢ 𝐾 = (𝐵 / 𝑆) & ⊢ (𝜑 → 𝑇 ∈ 𝑍) & ⊢ (𝜑 → 𝑅 Er 𝑈) & ⊢ (𝜑 → 𝑆 Er 𝑉) & ⊢ (𝜑 → 𝑇 Er 𝑊) & ⊢ (𝜑 → 𝐴 ⊆ 𝑈) & ⊢ (𝜑 → 𝐵 ⊆ 𝑉) & ⊢ (𝜑 → 𝐶 ⊆ 𝑊) & ⊢ (𝜑 → + :(𝐴 × 𝐵)⟶𝐶) & ⊢ ((𝜑 ∧ ((𝑟 ∈ 𝐴 ∧ 𝑠 ∈ 𝐴) ∧ (𝑡 ∈ 𝐵 ∧ 𝑢 ∈ 𝐵))) → ((𝑟𝑅𝑠 ∧ 𝑡𝑆𝑢) → (𝑟 + 𝑡)𝑇(𝑠 + 𝑢))) & ⊢ ⨣ = {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 ((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)} & ⊢ (𝜑 → 𝑅 ∈ 𝑋) & ⊢ (𝜑 → 𝑆 ∈ 𝑌) & ⊢ 𝐿 = (𝐶 / 𝑇) ⇒ ⊢ (𝜑 → ⨣ :(𝐽 × 𝐾)⟶𝐿) | ||
| Theorem | erov2 8856* | The value of an operation defined on equivalence classes. (Contributed by Jeff Madsen, 10-Jun-2010.) |
| ⊢ 𝐽 = (𝐴 / ∼ ) & ⊢ ⨣ = {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐴 ((𝑥 = [𝑝] ∼ ∧ 𝑦 = [𝑞] ∼ ) ∧ 𝑧 = [(𝑝 + 𝑞)] ∼ )} & ⊢ (𝜑 → ∼ ∈ 𝑋) & ⊢ (𝜑 → ∼ Er 𝑈) & ⊢ (𝜑 → 𝐴 ⊆ 𝑈) & ⊢ (𝜑 → + :(𝐴 × 𝐴)⟶𝐴) & ⊢ ((𝜑 ∧ ((𝑟 ∈ 𝐴 ∧ 𝑠 ∈ 𝐴) ∧ (𝑡 ∈ 𝐴 ∧ 𝑢 ∈ 𝐴))) → ((𝑟 ∼ 𝑠 ∧ 𝑡 ∼ 𝑢) → (𝑟 + 𝑡) ∼ (𝑠 + 𝑢))) ⇒ ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐴) → ([𝑃] ∼ ⨣ [𝑄] ∼ ) = [(𝑃 + 𝑄)] ∼ ) | ||
| Theorem | eroprf2 8857* | Functionality of an operation defined on equivalence classes. (Contributed by Jeff Madsen, 10-Jun-2010.) |
| ⊢ 𝐽 = (𝐴 / ∼ ) & ⊢ ⨣ = {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐴 ((𝑥 = [𝑝] ∼ ∧ 𝑦 = [𝑞] ∼ ) ∧ 𝑧 = [(𝑝 + 𝑞)] ∼ )} & ⊢ (𝜑 → ∼ ∈ 𝑋) & ⊢ (𝜑 → ∼ Er 𝑈) & ⊢ (𝜑 → 𝐴 ⊆ 𝑈) & ⊢ (𝜑 → + :(𝐴 × 𝐴)⟶𝐴) & ⊢ ((𝜑 ∧ ((𝑟 ∈ 𝐴 ∧ 𝑠 ∈ 𝐴) ∧ (𝑡 ∈ 𝐴 ∧ 𝑢 ∈ 𝐴))) → ((𝑟 ∼ 𝑠 ∧ 𝑡 ∼ 𝑢) → (𝑟 + 𝑡) ∼ (𝑠 + 𝑢))) ⇒ ⊢ (𝜑 → ⨣ :(𝐽 × 𝐽)⟶𝐽) | ||
| Theorem | ecopoveq 8858* | This is the first of several theorems about equivalence relations of the kind used in construction of fractions and signed reals, involving operations on equivalent classes of ordered pairs. This theorem expresses the relation ∼ (specified by the hypothesis) in terms of its operation 𝐹. (Contributed by NM, 16-Aug-1995.) |
| ⊢ ∼ = {〈𝑥, 𝑦〉 ∣ ((𝑥 ∈ (𝑆 × 𝑆) ∧ 𝑦 ∈ (𝑆 × 𝑆)) ∧ ∃𝑧∃𝑤∃𝑣∃𝑢((𝑥 = 〈𝑧, 𝑤〉 ∧ 𝑦 = 〈𝑣, 𝑢〉) ∧ (𝑧 + 𝑢) = (𝑤 + 𝑣)))} ⇒ ⊢ (((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑆 ∧ 𝐷 ∈ 𝑆)) → (〈𝐴, 𝐵〉 ∼ 〈𝐶, 𝐷〉 ↔ (𝐴 + 𝐷) = (𝐵 + 𝐶))) | ||
| Theorem | ecopovsym 8859* | Assuming the operation 𝐹 is commutative, show that the relation ∼, specified by the first hypothesis, is symmetric. (Contributed by NM, 27-Aug-1995.) (Revised by Mario Carneiro, 26-Apr-2015.) |
| ⊢ ∼ = {〈𝑥, 𝑦〉 ∣ ((𝑥 ∈ (𝑆 × 𝑆) ∧ 𝑦 ∈ (𝑆 × 𝑆)) ∧ ∃𝑧∃𝑤∃𝑣∃𝑢((𝑥 = 〈𝑧, 𝑤〉 ∧ 𝑦 = 〈𝑣, 𝑢〉) ∧ (𝑧 + 𝑢) = (𝑤 + 𝑣)))} & ⊢ (𝑥 + 𝑦) = (𝑦 + 𝑥) ⇒ ⊢ (𝐴 ∼ 𝐵 → 𝐵 ∼ 𝐴) | ||
| Theorem | ecopovtrn 8860* | Assuming that operation 𝐹 is commutative (second hypothesis), closed (third hypothesis), associative (fourth hypothesis), and has the cancellation property (fifth hypothesis), show that the relation ∼, specified by the first hypothesis, is transitive. (Contributed by NM, 11-Feb-1996.) (Revised by Mario Carneiro, 26-Apr-2015.) |
| ⊢ ∼ = {〈𝑥, 𝑦〉 ∣ ((𝑥 ∈ (𝑆 × 𝑆) ∧ 𝑦 ∈ (𝑆 × 𝑆)) ∧ ∃𝑧∃𝑤∃𝑣∃𝑢((𝑥 = 〈𝑧, 𝑤〉 ∧ 𝑦 = 〈𝑣, 𝑢〉) ∧ (𝑧 + 𝑢) = (𝑤 + 𝑣)))} & ⊢ (𝑥 + 𝑦) = (𝑦 + 𝑥) & ⊢ ((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) → (𝑥 + 𝑦) ∈ 𝑆) & ⊢ ((𝑥 + 𝑦) + 𝑧) = (𝑥 + (𝑦 + 𝑧)) & ⊢ ((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) → ((𝑥 + 𝑦) = (𝑥 + 𝑧) → 𝑦 = 𝑧)) ⇒ ⊢ ((𝐴 ∼ 𝐵 ∧ 𝐵 ∼ 𝐶) → 𝐴 ∼ 𝐶) | ||
| Theorem | ecopover 8861* | Assuming that operation 𝐹 is commutative (second hypothesis), closed (third hypothesis), associative (fourth hypothesis), and has the cancellation property (fifth hypothesis), show that the relation ∼, specified by the first hypothesis, is an equivalence relation. (Contributed by NM, 16-Feb-1996.) (Revised by Mario Carneiro, 12-Aug-2015.) (Proof shortened by AV, 1-May-2021.) |
| ⊢ ∼ = {〈𝑥, 𝑦〉 ∣ ((𝑥 ∈ (𝑆 × 𝑆) ∧ 𝑦 ∈ (𝑆 × 𝑆)) ∧ ∃𝑧∃𝑤∃𝑣∃𝑢((𝑥 = 〈𝑧, 𝑤〉 ∧ 𝑦 = 〈𝑣, 𝑢〉) ∧ (𝑧 + 𝑢) = (𝑤 + 𝑣)))} & ⊢ (𝑥 + 𝑦) = (𝑦 + 𝑥) & ⊢ ((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) → (𝑥 + 𝑦) ∈ 𝑆) & ⊢ ((𝑥 + 𝑦) + 𝑧) = (𝑥 + (𝑦 + 𝑧)) & ⊢ ((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) → ((𝑥 + 𝑦) = (𝑥 + 𝑧) → 𝑦 = 𝑧)) ⇒ ⊢ ∼ Er (𝑆 × 𝑆) | ||
| Theorem | eceqoveq 8862* | Equality of equivalence relation in terms of an operation. (Contributed by NM, 15-Feb-1996.) (Proof shortened by Mario Carneiro, 12-Aug-2015.) |
| ⊢ ∼ Er (𝑆 × 𝑆) & ⊢ dom + = (𝑆 × 𝑆) & ⊢ ¬ ∅ ∈ 𝑆 & ⊢ ((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) → (𝑥 + 𝑦) ∈ 𝑆) & ⊢ (((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑆 ∧ 𝐷 ∈ 𝑆)) → (〈𝐴, 𝐵〉 ∼ 〈𝐶, 𝐷〉 ↔ (𝐴 + 𝐷) = (𝐵 + 𝐶))) ⇒ ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐶 ∈ 𝑆) → ([〈𝐴, 𝐵〉] ∼ = [〈𝐶, 𝐷〉] ∼ ↔ (𝐴 + 𝐷) = (𝐵 + 𝐶))) | ||
| Theorem | ecovcom 8863* | Lemma used to transfer a commutative law via an equivalence relation. (Contributed by NM, 29-Aug-1995.) (Revised by David Abernethy, 4-Jun-2013.) |
| ⊢ 𝐶 = ((𝑆 × 𝑆) / ∼ ) & ⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆)) → ([〈𝑥, 𝑦〉] ∼ + [〈𝑧, 𝑤〉] ∼ ) = [〈𝐷, 𝐺〉] ∼ ) & ⊢ (((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → ([〈𝑧, 𝑤〉] ∼ + [〈𝑥, 𝑦〉] ∼ ) = [〈𝐻, 𝐽〉] ∼ ) & ⊢ 𝐷 = 𝐻 & ⊢ 𝐺 = 𝐽 ⇒ ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) → (𝐴 + 𝐵) = (𝐵 + 𝐴)) | ||
| Theorem | ecovass 8864* | Lemma used to transfer an associative law via an equivalence relation. (Contributed by NM, 31-Aug-1995.) (Revised by David Abernethy, 4-Jun-2013.) |
| ⊢ 𝐷 = ((𝑆 × 𝑆) / ∼ ) & ⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆)) → ([〈𝑥, 𝑦〉] ∼ + [〈𝑧, 𝑤〉] ∼ ) = [〈𝐺, 𝐻〉] ∼ ) & ⊢ (((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ ) = [〈𝑁, 𝑄〉] ∼ ) & ⊢ (((𝐺 ∈ 𝑆 ∧ 𝐻 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → ([〈𝐺, 𝐻〉] ∼ + [〈𝑣, 𝑢〉] ∼ ) = [〈𝐽, 𝐾〉] ∼ ) & ⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑁 ∈ 𝑆 ∧ 𝑄 ∈ 𝑆)) → ([〈𝑥, 𝑦〉] ∼ + [〈𝑁, 𝑄〉] ∼ ) = [〈𝐿, 𝑀〉] ∼ ) & ⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆)) → (𝐺 ∈ 𝑆 ∧ 𝐻 ∈ 𝑆)) & ⊢ (((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → (𝑁 ∈ 𝑆 ∧ 𝑄 ∈ 𝑆)) & ⊢ 𝐽 = 𝐿 & ⊢ 𝐾 = 𝑀 ⇒ ⊢ ((𝐴 ∈ 𝐷 ∧ 𝐵 ∈ 𝐷 ∧ 𝐶 ∈ 𝐷) → ((𝐴 + 𝐵) + 𝐶) = (𝐴 + (𝐵 + 𝐶))) | ||
| Theorem | ecovdi 8865* | Lemma used to transfer a distributive law via an equivalence relation. (Contributed by NM, 2-Sep-1995.) (Revised by David Abernethy, 4-Jun-2013.) |
| ⊢ 𝐷 = ((𝑆 × 𝑆) / ∼ ) & ⊢ (((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ ) = [〈𝑀, 𝑁〉] ∼ ) & ⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑀 ∈ 𝑆 ∧ 𝑁 ∈ 𝑆)) → ([〈𝑥, 𝑦〉] ∼ · [〈𝑀, 𝑁〉] ∼ ) = [〈𝐻, 𝐽〉] ∼ ) & ⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆)) → ([〈𝑥, 𝑦〉] ∼ · [〈𝑧, 𝑤〉] ∼ ) = [〈𝑊, 𝑋〉] ∼ ) & ⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → ([〈𝑥, 𝑦〉] ∼ · [〈𝑣, 𝑢〉] ∼ ) = [〈𝑌, 𝑍〉] ∼ ) & ⊢ (((𝑊 ∈ 𝑆 ∧ 𝑋 ∈ 𝑆) ∧ (𝑌 ∈ 𝑆 ∧ 𝑍 ∈ 𝑆)) → ([〈𝑊, 𝑋〉] ∼ + [〈𝑌, 𝑍〉] ∼ ) = [〈𝐾, 𝐿〉] ∼ ) & ⊢ (((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → (𝑀 ∈ 𝑆 ∧ 𝑁 ∈ 𝑆)) & ⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆)) → (𝑊 ∈ 𝑆 ∧ 𝑋 ∈ 𝑆)) & ⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → (𝑌 ∈ 𝑆 ∧ 𝑍 ∈ 𝑆)) & ⊢ 𝐻 = 𝐾 & ⊢ 𝐽 = 𝐿 ⇒ ⊢ ((𝐴 ∈ 𝐷 ∧ 𝐵 ∈ 𝐷 ∧ 𝐶 ∈ 𝐷) → (𝐴 · (𝐵 + 𝐶)) = ((𝐴 · 𝐵) + (𝐴 · 𝐶))) | ||
| Syntax | cmap 8866 | Extend the definition of a class to include the mapping operation. (Read for 𝐴 ↑m 𝐵, "the set of all functions that map from 𝐵 to 𝐴.) |
| class ↑m | ||
| Syntax | cpm 8867 | Extend the definition of a class to include the partial mapping operation. (Read for 𝐴 ↑pm 𝐵, "the set of all partial functions that map from 𝐵 to 𝐴.) |
| class ↑pm | ||
| Definition | df-map 8868* | Define the mapping operation or set exponentiation. The set of all functions that map from 𝐵 to 𝐴 is written (𝐴 ↑m 𝐵) (see mapval 8878). Many authors write 𝐴 followed by 𝐵 as a superscript for this operation and rely on context to avoid confusion other exponentiation operations (e.g., Definition 10.42 of [TakeutiZaring] p. 95). Other authors show 𝐵 as a prefixed superscript, which is read "𝐴 pre 𝐵 " (e.g., definition of [Enderton] p. 52). Definition 8.21 of [Eisenberg] p. 125 uses the notation Map(𝐵, 𝐴) for our (𝐴 ↑m 𝐵). The up-arrow is used by Donald Knuth for iterated exponentiation (Science 194, 1235-1242, 1976). We adopt the first case of his notation (simple exponentiation) and subscript it with m to distinguish it from other kinds of exponentiation. (Contributed by NM, 8-Dec-2003.) |
| ⊢ ↑m = (𝑥 ∈ V, 𝑦 ∈ V ↦ {𝑓 ∣ 𝑓:𝑦⟶𝑥}) | ||
| Definition | df-pm 8869* | Define the partial mapping operation. A partial function from 𝐵 to 𝐴 is a function from a subset of 𝐵 to 𝐴. The set of all partial functions from 𝐵 to 𝐴 is written (𝐴 ↑pm 𝐵) (see pmvalg 8877). A notation for this operation apparently does not appear in the literature. We use ↑pm to distinguish it from the less general set exponentiation operation ↑m (df-map 8868). See mapsspm 8916 for its relationship to set exponentiation. (Contributed by NM, 15-Nov-2007.) |
| ⊢ ↑pm = (𝑥 ∈ V, 𝑦 ∈ V ↦ {𝑓 ∈ 𝒫 (𝑦 × 𝑥) ∣ Fun 𝑓}) | ||
| Theorem | mapprc 8870* | When 𝐴 is a proper class, the class of all functions mapping 𝐴 to 𝐵 is empty. Exercise 4.41 of [Mendelson] p. 255. (Contributed by NM, 8-Dec-2003.) |
| ⊢ (¬ 𝐴 ∈ V → {𝑓 ∣ 𝑓:𝐴⟶𝐵} = ∅) | ||
| Theorem | pmex 8871* | The class of all partial functions from one set to another is a set. (Contributed by NM, 15-Nov-2007.) |
| ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → {𝑓 ∣ (Fun 𝑓 ∧ 𝑓 ⊆ (𝐴 × 𝐵))} ∈ V) | ||
| Theorem | mapexOLD 8872* | Obsolete version of mapex 7963 as of 17-Jun-2025. (Contributed by Raph Levien, 4-Dec-2003.) (New usage is discouraged.) (Proof modification is discouraged.) |
| ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → {𝑓 ∣ 𝑓:𝐴⟶𝐵} ∈ V) | ||
| Theorem | fnmap 8873 | Set exponentiation has a universal domain. (Contributed by NM, 8-Dec-2003.) (Revised by Mario Carneiro, 8-Sep-2013.) |
| ⊢ ↑m Fn (V × V) | ||
| Theorem | fnpm 8874 | Partial function exponentiation has a universal domain. (Contributed by Mario Carneiro, 14-Nov-2013.) |
| ⊢ ↑pm Fn (V × V) | ||
| Theorem | reldmmap 8875 | Set exponentiation is a well-behaved binary operator. (Contributed by Stefan O'Rear, 27-Feb-2015.) |
| ⊢ Rel dom ↑m | ||
| Theorem | mapvalg 8876* | The value of set exponentiation. (𝐴 ↑m 𝐵) is the set of all functions that map from 𝐵 to 𝐴. Definition 10.24 of [Kunen] p. 24. (Contributed by NM, 8-Dec-2003.) (Revised by Mario Carneiro, 8-Sep-2013.) |
| ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → (𝐴 ↑m 𝐵) = {𝑓 ∣ 𝑓:𝐵⟶𝐴}) | ||
| Theorem | pmvalg 8877* | The value of the partial mapping operation. (𝐴 ↑pm 𝐵) is the set of all partial functions that map from 𝐵 to 𝐴. (Contributed by NM, 15-Nov-2007.) (Revised by Mario Carneiro, 8-Sep-2013.) |
| ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → (𝐴 ↑pm 𝐵) = {𝑓 ∈ 𝒫 (𝐵 × 𝐴) ∣ Fun 𝑓}) | ||
| Theorem | mapval 8878* | The value of set exponentiation (inference version). (𝐴 ↑m 𝐵) is the set of all functions that map from 𝐵 to 𝐴. Definition 10.24 of [Kunen] p. 24. (Contributed by NM, 8-Dec-2003.) |
| ⊢ 𝐴 ∈ V & ⊢ 𝐵 ∈ V ⇒ ⊢ (𝐴 ↑m 𝐵) = {𝑓 ∣ 𝑓:𝐵⟶𝐴} | ||
| Theorem | elmapg 8879 | Membership relation for set exponentiation. (Contributed by NM, 17-Oct-2006.) (Revised by Mario Carneiro, 15-Nov-2014.) |
| ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐶 ∈ (𝐴 ↑m 𝐵) ↔ 𝐶:𝐵⟶𝐴)) | ||
| Theorem | elmapd 8880 | Deduction form of elmapg 8879. (Contributed by BJ, 11-Apr-2020.) |
| ⊢ (𝜑 → 𝐴 ∈ 𝑉) & ⊢ (𝜑 → 𝐵 ∈ 𝑊) ⇒ ⊢ (𝜑 → (𝐶 ∈ (𝐴 ↑m 𝐵) ↔ 𝐶:𝐵⟶𝐴)) | ||
| Theorem | elmapdd 8881 | Deduction associated with elmapd 8880. (Contributed by SN, 29-Jul-2024.) |
| ⊢ (𝜑 → 𝐴 ∈ 𝑉) & ⊢ (𝜑 → 𝐵 ∈ 𝑊) & ⊢ (𝜑 → 𝐶:𝐵⟶𝐴) ⇒ ⊢ (𝜑 → 𝐶 ∈ (𝐴 ↑m 𝐵)) | ||
| Theorem | mapdm0 8882 | The empty set is the only map with empty domain. (Contributed by Glauco Siliprandi, 11-Oct-2020.) (Proof shortened by Thierry Arnoux, 3-Dec-2021.) |
| ⊢ (𝐵 ∈ 𝑉 → (𝐵 ↑m ∅) = {∅}) | ||
| Theorem | elpmg 8883 | The predicate "is a partial function". (Contributed by Mario Carneiro, 14-Nov-2013.) |
| ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐶 ∈ (𝐴 ↑pm 𝐵) ↔ (Fun 𝐶 ∧ 𝐶 ⊆ (𝐵 × 𝐴)))) | ||
| Theorem | elpm2g 8884 | The predicate "is a partial function". (Contributed by NM, 31-Dec-2013.) |
| ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐹 ∈ (𝐴 ↑pm 𝐵) ↔ (𝐹:dom 𝐹⟶𝐴 ∧ dom 𝐹 ⊆ 𝐵))) | ||
| Theorem | elpm2r 8885 | Sufficient condition for being a partial function. (Contributed by NM, 31-Dec-2013.) |
| ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ (𝐹:𝐶⟶𝐴 ∧ 𝐶 ⊆ 𝐵)) → 𝐹 ∈ (𝐴 ↑pm 𝐵)) | ||
| Theorem | elpmi 8886 | A partial function is a function. (Contributed by Mario Carneiro, 15-Sep-2015.) |
| ⊢ (𝐹 ∈ (𝐴 ↑pm 𝐵) → (𝐹:dom 𝐹⟶𝐴 ∧ dom 𝐹 ⊆ 𝐵)) | ||
| Theorem | pmfun 8887 | A partial function is a function. (Contributed by Mario Carneiro, 30-Jan-2014.) (Revised by Mario Carneiro, 26-Apr-2015.) |
| ⊢ (𝐹 ∈ (𝐴 ↑pm 𝐵) → Fun 𝐹) | ||
| Theorem | elmapex 8888 | Eliminate antecedent for mapping theorems: domain can be taken to be a set. (Contributed by Stefan O'Rear, 8-Oct-2014.) |
| ⊢ (𝐴 ∈ (𝐵 ↑m 𝐶) → (𝐵 ∈ V ∧ 𝐶 ∈ V)) | ||
| Theorem | elmapi 8889 | A mapping is a function, forward direction only with superfluous antecedent removed. (Contributed by Stefan O'Rear, 10-Oct-2014.) |
| ⊢ (𝐴 ∈ (𝐵 ↑m 𝐶) → 𝐴:𝐶⟶𝐵) | ||
| Theorem | mapfset 8890* | If 𝐵 is a set, the value of the set exponentiation (𝐵 ↑m 𝐴) is the class of all functions from 𝐴 to 𝐵. Generalisation of mapvalg 8876 (which does not require ax-rep 5279) to arbitrary domains. Note that the class {𝑓 ∣ 𝑓:𝐴⟶𝐵} can only contain set-functions, as opposed to arbitrary class-functions. When 𝐴 is a proper class, there can be no set-functions on it, so the above class is empty (see also fsetdmprc0 8895), hence a set. In this case, both sides of the equality in this theorem are the empty set. (Contributed by AV, 8-Aug-2024.) |
| ⊢ (𝐵 ∈ 𝑉 → {𝑓 ∣ 𝑓:𝐴⟶𝐵} = (𝐵 ↑m 𝐴)) | ||
| Theorem | mapssfset 8891* | The value of the set exponentiation (𝐵 ↑m 𝐴) is a subset of the class of functions from 𝐴 to 𝐵. (Contributed by AV, 10-Aug-2024.) |
| ⊢ (𝐵 ↑m 𝐴) ⊆ {𝑓 ∣ 𝑓:𝐴⟶𝐵} | ||
| Theorem | mapfoss 8892* | The value of the set exponentiation (𝐵 ↑m 𝐴) is a superset of the set of all functions from 𝐴 onto 𝐵. (Contributed by AV, 7-Aug-2024.) |
| ⊢ {𝑓 ∣ 𝑓:𝐴–onto→𝐵} ⊆ (𝐵 ↑m 𝐴) | ||
| Theorem | fsetsspwxp 8893* | The class of all functions from 𝐴 into 𝐵 is a subclass of the power class of the cartesion product of 𝐴 and 𝐵. (Contributed by AV, 13-Sep-2024.) |
| ⊢ {𝑓 ∣ 𝑓:𝐴⟶𝐵} ⊆ 𝒫 (𝐴 × 𝐵) | ||
| Theorem | fset0 8894 | The set of functions from the empty set is the singleton containing the empty set. (Contributed by AV, 13-Sep-2024.) |
| ⊢ {𝑓 ∣ 𝑓:∅⟶𝐵} = {∅} | ||
| Theorem | fsetdmprc0 8895* | The set of functions with a proper class as domain is empty. (Contributed by AV, 22-Aug-2024.) |
| ⊢ (𝐴 ∉ V → {𝑓 ∣ 𝑓 Fn 𝐴} = ∅) | ||
| Theorem | fsetex 8896* | The set of functions between two classes exists if the codomain exists. Generalization of mapex 7963 to arbitrary domains. (Contributed by AV, 14-Aug-2024.) |
| ⊢ (𝐵 ∈ 𝑉 → {𝑓 ∣ 𝑓:𝐴⟶𝐵} ∈ V) | ||
| Theorem | f1setex 8897* | The set of injections between two classes exists if the codomain exists. (Contributed by AV, 14-Aug-2024.) |
| ⊢ (𝐵 ∈ 𝑉 → {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ∈ V) | ||
| Theorem | fosetex 8898* | The set of surjections between two classes exists (without any precondition). (Contributed by AV, 8-Aug-2024.) |
| ⊢ {𝑓 ∣ 𝑓:𝐴–onto→𝐵} ∈ V | ||
| Theorem | f1osetex 8899* | The set of bijections between two classes exists. (Contributed by AV, 30-Mar-2024.) (Revised by AV, 8-Aug-2024.) (Proof shortened by SN, 22-Aug-2024.) |
| ⊢ {𝑓 ∣ 𝑓:𝐴–1-1-onto→𝐵} ∈ V | ||
| Theorem | fsetfcdm 8900* | The class of functions with a given domain and a given codomain is mapped, through evaluation at a point of the domain, into the codomain. (Contributed by AV, 15-Sep-2024.) |
| ⊢ 𝐹 = {𝑓 ∣ 𝑓:𝐴⟶𝐵} & ⊢ 𝑆 = (𝑔 ∈ 𝐹 ↦ (𝑔‘𝑋)) ⇒ ⊢ (𝑋 ∈ 𝐴 → 𝑆:𝐹⟶𝐵) | ||
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