Home | Metamath
Proof Explorer Theorem List (p. 77 of 449) | < Previous Next > |
Bad symbols? Try the
GIF version. |
||
Mirrors > Metamath Home Page > MPE Home Page > Theorem List Contents > Recent Proofs This page: Page List |
Color key: | Metamath Proof Explorer
(1-28689) |
Hilbert Space Explorer
(28690-30212) |
Users' Mathboxes
(30213-44899) |
Type | Label | Description |
---|---|---|
Statement | ||
Theorem | find 7601* | The Principle of Finite Induction (mathematical induction). Corollary 7.31 of [TakeutiZaring] p. 43. The simpler hypothesis shown here was suggested in an email from "Colin" on 1-Oct-2001. The hypothesis states that 𝐴 is a set of natural numbers, zero belongs to 𝐴, and given any member of 𝐴 the member's successor also belongs to 𝐴. The conclusion is that every natural number is in 𝐴. (Contributed by NM, 22-Feb-2004.) (Proof shortened by Andrew Salmon, 27-Aug-2011.) |
⊢ (𝐴 ⊆ ω ∧ ∅ ∈ 𝐴 ∧ ∀𝑥 ∈ 𝐴 suc 𝑥 ∈ 𝐴) ⇒ ⊢ 𝐴 = ω | ||
Theorem | finds 7602* | Principle of Finite Induction (inference schema), using implicit substitutions. The first four hypotheses establish the substitutions we need. The last two are the basis and the induction step. Theorem Schema 22 of [Suppes] p. 136. This is Metamath 100 proof #74. (Contributed by NM, 14-Apr-1995.) |
⊢ (𝑥 = ∅ → (𝜑 ↔ 𝜓)) & ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜒)) & ⊢ (𝑥 = suc 𝑦 → (𝜑 ↔ 𝜃)) & ⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜏)) & ⊢ 𝜓 & ⊢ (𝑦 ∈ ω → (𝜒 → 𝜃)) ⇒ ⊢ (𝐴 ∈ ω → 𝜏) | ||
Theorem | findsg 7603* | Principle of Finite Induction (inference schema), using implicit substitutions. The first four hypotheses establish the substitutions we need. The last two are the basis and the induction step. The basis of this version is an arbitrary natural number 𝐵 instead of zero. (Contributed by NM, 16-Sep-1995.) |
⊢ (𝑥 = 𝐵 → (𝜑 ↔ 𝜓)) & ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜒)) & ⊢ (𝑥 = suc 𝑦 → (𝜑 ↔ 𝜃)) & ⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜏)) & ⊢ (𝐵 ∈ ω → 𝜓) & ⊢ (((𝑦 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐵 ⊆ 𝑦) → (𝜒 → 𝜃)) ⇒ ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐵 ⊆ 𝐴) → 𝜏) | ||
Theorem | finds2 7604* | Principle of Finite Induction (inference schema), using implicit substitutions. The first three hypotheses establish the substitutions we need. The last two are the basis and the induction step. Theorem Schema 22 of [Suppes] p. 136. (Contributed by NM, 29-Nov-2002.) |
⊢ (𝑥 = ∅ → (𝜑 ↔ 𝜓)) & ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜒)) & ⊢ (𝑥 = suc 𝑦 → (𝜑 ↔ 𝜃)) & ⊢ (𝜏 → 𝜓) & ⊢ (𝑦 ∈ ω → (𝜏 → (𝜒 → 𝜃))) ⇒ ⊢ (𝑥 ∈ ω → (𝜏 → 𝜑)) | ||
Theorem | finds1 7605* | Principle of Finite Induction (inference schema), using implicit substitutions. The first three hypotheses establish the substitutions we need. The last two are the basis and the induction step. Theorem Schema 22 of [Suppes] p. 136. (Contributed by NM, 22-Mar-2006.) |
⊢ (𝑥 = ∅ → (𝜑 ↔ 𝜓)) & ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜒)) & ⊢ (𝑥 = suc 𝑦 → (𝜑 ↔ 𝜃)) & ⊢ 𝜓 & ⊢ (𝑦 ∈ ω → (𝜒 → 𝜃)) ⇒ ⊢ (𝑥 ∈ ω → 𝜑) | ||
Theorem | findes 7606 | Finite induction with explicit substitution. The first hypothesis is the basis and the second is the induction step. Theorem Schema 22 of [Suppes] p. 136. See tfindes 7571 for the transfinite version. This is an alternative for Metamath 100 proof #74. (Contributed by Raph Levien, 9-Jul-2003.) |
⊢ [∅ / 𝑥]𝜑 & ⊢ (𝑥 ∈ ω → (𝜑 → [suc 𝑥 / 𝑥]𝜑)) ⇒ ⊢ (𝑥 ∈ ω → 𝜑) | ||
Theorem | dmexg 7607 | The domain of a set is a set. Corollary 6.8(2) of [TakeutiZaring] p. 26. (Contributed by NM, 7-Apr-1995.) |
⊢ (𝐴 ∈ 𝑉 → dom 𝐴 ∈ V) | ||
Theorem | rnexg 7608 | The range of a set is a set. Corollary 6.8(3) of [TakeutiZaring] p. 26. Similar to Lemma 3D of [Enderton] p. 41. (Contributed by NM, 31-Mar-1995.) |
⊢ (𝐴 ∈ 𝑉 → ran 𝐴 ∈ V) | ||
Theorem | dmexd 7609 | The domain of a set is a set. (Contributed by Glauco Siliprandi, 26-Jun-2021.) |
⊢ (𝜑 → 𝐴 ∈ 𝑉) ⇒ ⊢ (𝜑 → dom 𝐴 ∈ V) | ||
Theorem | dmex 7610 | The domain of a set is a set. Corollary 6.8(2) of [TakeutiZaring] p. 26. (Contributed by NM, 7-Jul-2008.) |
⊢ 𝐴 ∈ V ⇒ ⊢ dom 𝐴 ∈ V | ||
Theorem | rnex 7611 | The range of a set is a set. Corollary 6.8(3) of [TakeutiZaring] p. 26. Similar to Lemma 3D of [Enderton] p. 41. (Contributed by NM, 7-Jul-2008.) |
⊢ 𝐴 ∈ V ⇒ ⊢ ran 𝐴 ∈ V | ||
Theorem | iprc 7612 | The identity function is a proper class. This means, for example, that we cannot use it as a member of the class of continuous functions unless it is restricted to a set, as in idcn 21859. (Contributed by NM, 1-Jan-2007.) |
⊢ ¬ I ∈ V | ||
Theorem | resiexg 7613 | The existence of a restricted identity function, proved without using the Axiom of Replacement (unlike resfunexg 6972). (Contributed by NM, 13-Jan-2007.) (Proof shortened by Peter Mazsa, 2-Oct-2022.) |
⊢ (𝐴 ∈ 𝑉 → ( I ↾ 𝐴) ∈ V) | ||
Theorem | imaexg 7614 | The image of a set is a set. Theorem 3.17 of [Monk1] p. 39. (Contributed by NM, 24-Jul-1995.) |
⊢ (𝐴 ∈ 𝑉 → (𝐴 “ 𝐵) ∈ V) | ||
Theorem | imaex 7615 | The image of a set is a set. Theorem 3.17 of [Monk1] p. 39. (Contributed by JJ, 24-Sep-2021.) |
⊢ 𝐴 ∈ V ⇒ ⊢ (𝐴 “ 𝐵) ∈ V | ||
Theorem | exse2 7616 | Any set relation is set-like. (Contributed by Mario Carneiro, 22-Jun-2015.) |
⊢ (𝑅 ∈ 𝑉 → 𝑅 Se 𝐴) | ||
Theorem | xpexr 7617 | If a Cartesian product is a set, one of its components must be a set. (Contributed by NM, 27-Aug-2006.) |
⊢ ((𝐴 × 𝐵) ∈ 𝐶 → (𝐴 ∈ V ∨ 𝐵 ∈ V)) | ||
Theorem | xpexr2 7618 | If a nonempty Cartesian product is a set, so are both of its components. (Contributed by NM, 27-Aug-2006.) |
⊢ (((𝐴 × 𝐵) ∈ 𝐶 ∧ (𝐴 × 𝐵) ≠ ∅) → (𝐴 ∈ V ∧ 𝐵 ∈ V)) | ||
Theorem | xpexcnv 7619 | A condition where the converse of xpex 7470 holds as well. Corollary 6.9(2) in [TakeutiZaring] p. 26. (Contributed by Andrew Salmon, 13-Nov-2011.) |
⊢ ((𝐵 ≠ ∅ ∧ (𝐴 × 𝐵) ∈ V) → 𝐴 ∈ V) | ||
Theorem | soex 7620 | If the relation in a strict order is a set, then the base field is also a set. (Contributed by Mario Carneiro, 27-Apr-2015.) |
⊢ ((𝑅 Or 𝐴 ∧ 𝑅 ∈ 𝑉) → 𝐴 ∈ V) | ||
Theorem | elxp4 7621 | Membership in a Cartesian product. This version requires no quantifiers or dummy variables. See also elxp5 7622, elxp6 7717, and elxp7 7718. (Contributed by NM, 17-Feb-2004.) |
⊢ (𝐴 ∈ (𝐵 × 𝐶) ↔ (𝐴 = 〈∪ dom {𝐴}, ∪ ran {𝐴}〉 ∧ (∪ dom {𝐴} ∈ 𝐵 ∧ ∪ ran {𝐴} ∈ 𝐶))) | ||
Theorem | elxp5 7622 | Membership in a Cartesian product requiring no quantifiers or dummy variables. Provides a slightly shorter version of elxp4 7621 when the double intersection does not create class existence problems (caused by int0 4883). (Contributed by NM, 1-Aug-2004.) |
⊢ (𝐴 ∈ (𝐵 × 𝐶) ↔ (𝐴 = 〈∩ ∩ 𝐴, ∪ ran {𝐴}〉 ∧ (∩ ∩ 𝐴 ∈ 𝐵 ∧ ∪ ran {𝐴} ∈ 𝐶))) | ||
Theorem | cnvexg 7623 | The converse of a set is a set. Corollary 6.8(1) of [TakeutiZaring] p. 26. (Contributed by NM, 17-Mar-1998.) |
⊢ (𝐴 ∈ 𝑉 → ◡𝐴 ∈ V) | ||
Theorem | cnvex 7624 | The converse of a set is a set. Corollary 6.8(1) of [TakeutiZaring] p. 26. (Contributed by NM, 19-Dec-2003.) |
⊢ 𝐴 ∈ V ⇒ ⊢ ◡𝐴 ∈ V | ||
Theorem | relcnvexb 7625 | A relation is a set iff its converse is a set. (Contributed by FL, 3-Mar-2007.) |
⊢ (Rel 𝑅 → (𝑅 ∈ V ↔ ◡𝑅 ∈ V)) | ||
Theorem | f1oexrnex 7626 | If the range of a 1-1 onto function is a set, the function itself is a set. (Contributed by AV, 2-Jun-2019.) |
⊢ ((𝐹:𝐴–1-1-onto→𝐵 ∧ 𝐵 ∈ 𝑉) → 𝐹 ∈ V) | ||
Theorem | f1oexbi 7627* | There is a one-to-one onto function from a set to a second set iff there is a one-to-one onto function from the second set to the first set. (Contributed by Alexander van der Vekens, 30-Sep-2018.) |
⊢ (∃𝑓 𝑓:𝐴–1-1-onto→𝐵 ↔ ∃𝑔 𝑔:𝐵–1-1-onto→𝐴) | ||
Theorem | coexg 7628 | The composition of two sets is a set. (Contributed by NM, 19-Mar-1998.) |
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 ∘ 𝐵) ∈ V) | ||
Theorem | coex 7629 | The composition of two sets is a set. (Contributed by NM, 15-Dec-2003.) |
⊢ 𝐴 ∈ V & ⊢ 𝐵 ∈ V ⇒ ⊢ (𝐴 ∘ 𝐵) ∈ V | ||
Theorem | funcnvuni 7630* | The union of a chain (with respect to inclusion) of single-rooted sets is single-rooted. (See funcnv 6418 for "single-rooted" definition.) (Contributed by NM, 11-Aug-2004.) |
⊢ (∀𝑓 ∈ 𝐴 (Fun ◡𝑓 ∧ ∀𝑔 ∈ 𝐴 (𝑓 ⊆ 𝑔 ∨ 𝑔 ⊆ 𝑓)) → Fun ◡∪ 𝐴) | ||
Theorem | fun11uni 7631* | The union of a chain (with respect to inclusion) of one-to-one functions is a one-to-one function. (Contributed by NM, 11-Aug-2004.) |
⊢ (∀𝑓 ∈ 𝐴 ((Fun 𝑓 ∧ Fun ◡𝑓) ∧ ∀𝑔 ∈ 𝐴 (𝑓 ⊆ 𝑔 ∨ 𝑔 ⊆ 𝑓)) → (Fun ∪ 𝐴 ∧ Fun ◡∪ 𝐴)) | ||
Theorem | fex2 7632 | A function with bounded domain and range is a set. This version of fex 6983 is proven without the Axiom of Replacement. (Contributed by Mario Carneiro, 24-Jun-2015.) |
⊢ ((𝐹:𝐴⟶𝐵 ∧ 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → 𝐹 ∈ V) | ||
Theorem | fabexg 7633* | Existence of a set of functions. (Contributed by Paul Chapman, 25-Feb-2008.) |
⊢ 𝐹 = {𝑥 ∣ (𝑥:𝐴⟶𝐵 ∧ 𝜑)} ⇒ ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → 𝐹 ∈ V) | ||
Theorem | fabex 7634* | Existence of a set of functions. (Contributed by NM, 3-Dec-2007.) |
⊢ 𝐴 ∈ V & ⊢ 𝐵 ∈ V & ⊢ 𝐹 = {𝑥 ∣ (𝑥:𝐴⟶𝐵 ∧ 𝜑)} ⇒ ⊢ 𝐹 ∈ V | ||
Theorem | dmfex 7635 | If a mapping is a set, its domain is a set. (Contributed by NM, 27-Aug-2006.) (Proof shortened by Andrew Salmon, 17-Sep-2011.) |
⊢ ((𝐹 ∈ 𝐶 ∧ 𝐹:𝐴⟶𝐵) → 𝐴 ∈ V) | ||
Theorem | f1oabexg 7636* | The class of all 1-1-onto functions mapping one set to another is a set. (Contributed by Paul Chapman, 25-Feb-2008.) |
⊢ 𝐹 = {𝑓 ∣ (𝑓:𝐴–1-1-onto→𝐵 ∧ 𝜑)} ⇒ ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → 𝐹 ∈ V) | ||
Theorem | fiunlem 7637* | Lemma for fiun 7638 and f1iun 7639. Formerly part of f1iun 7639. (Contributed by AV, 6-Oct-2023.) |
⊢ (𝑥 = 𝑦 → 𝐵 = 𝐶) ⇒ ⊢ (((𝐵:𝐷⟶𝑆 ∧ ∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)) ∧ 𝑢 = 𝐵) → ∀𝑣 ∈ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 = 𝐵} (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢)) | ||
Theorem | fiun 7638* | The union of a chain (with respect to inclusion) of functions is a function. Analogous to f1iun 7639. (Contributed by AV, 6-Oct-2023.) |
⊢ (𝑥 = 𝑦 → 𝐵 = 𝐶) & ⊢ 𝐵 ∈ V ⇒ ⊢ (∀𝑥 ∈ 𝐴 (𝐵:𝐷⟶𝑆 ∧ ∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)) → ∪ 𝑥 ∈ 𝐴 𝐵:∪ 𝑥 ∈ 𝐴 𝐷⟶𝑆) | ||
Theorem | f1iun 7639* | The union of a chain (with respect to inclusion) of one-to-one functions is a one-to-one function. (Contributed by Mario Carneiro, 20-May-2013.) (Revised by Mario Carneiro, 24-Jun-2015.) (Proof shortened by AV, 5-Nov-2023.) |
⊢ (𝑥 = 𝑦 → 𝐵 = 𝐶) & ⊢ 𝐵 ∈ V ⇒ ⊢ (∀𝑥 ∈ 𝐴 (𝐵:𝐷–1-1→𝑆 ∧ ∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)) → ∪ 𝑥 ∈ 𝐴 𝐵:∪ 𝑥 ∈ 𝐴 𝐷–1-1→𝑆) | ||
Theorem | fviunfun 7640* | The function value of an indexed union is the value of one of the indexed functions. (Contributed by AV, 4-Nov-2023.) |
⊢ 𝑈 = ∪ 𝑖 ∈ 𝐼 (𝐹‘𝑖) ⇒ ⊢ ((Fun 𝑈 ∧ 𝐽 ∈ 𝐼 ∧ 𝑋 ∈ dom (𝐹‘𝐽)) → (𝑈‘𝑋) = ((𝐹‘𝐽)‘𝑋)) | ||
Theorem | ffoss 7641* | Relationship between a mapping and an onto mapping. Figure 38 of [Enderton] p. 145. (Contributed by NM, 10-May-1998.) |
⊢ 𝐹 ∈ V ⇒ ⊢ (𝐹:𝐴⟶𝐵 ↔ ∃𝑥(𝐹:𝐴–onto→𝑥 ∧ 𝑥 ⊆ 𝐵)) | ||
Theorem | f11o 7642* | Relationship between one-to-one and one-to-one onto function. (Contributed by NM, 4-Apr-1998.) |
⊢ 𝐹 ∈ V ⇒ ⊢ (𝐹:𝐴–1-1→𝐵 ↔ ∃𝑥(𝐹:𝐴–1-1-onto→𝑥 ∧ 𝑥 ⊆ 𝐵)) | ||
Theorem | resfunexgALT 7643 | Alternate proof of resfunexg 6972, shorter but requiring ax-pow 5259 and ax-un 7455. (Contributed by NM, 7-Apr-1995.) (Proof modification is discouraged.) (New usage is discouraged.) |
⊢ ((Fun 𝐴 ∧ 𝐵 ∈ 𝐶) → (𝐴 ↾ 𝐵) ∈ V) | ||
Theorem | cofunexg 7644 | Existence of a composition when the first member is a function. (Contributed by NM, 8-Oct-2007.) |
⊢ ((Fun 𝐴 ∧ 𝐵 ∈ 𝐶) → (𝐴 ∘ 𝐵) ∈ V) | ||
Theorem | cofunex2g 7645 | Existence of a composition when the second member is one-to-one. (Contributed by NM, 8-Oct-2007.) |
⊢ ((𝐴 ∈ 𝑉 ∧ Fun ◡𝐵) → (𝐴 ∘ 𝐵) ∈ V) | ||
Theorem | fnexALT 7646 | Alternate proof of fnex 6974, derived using the Axiom of Replacement in the form of funimaexg 6435. This version uses ax-pow 5259 and ax-un 7455, whereas fnex 6974 does not. (Contributed by NM, 14-Aug-1994.) (Proof modification is discouraged.) (New usage is discouraged.) |
⊢ ((𝐹 Fn 𝐴 ∧ 𝐴 ∈ 𝐵) → 𝐹 ∈ V) | ||
Theorem | funexw 7647 | Weak version of funex 6976 that holds without ax-rep 5183. If the domain and codomain of a function exist, so does the function. (Contributed by Rohan Ridenour, 13-Aug-2023.) |
⊢ ((Fun 𝐹 ∧ dom 𝐹 ∈ 𝐵 ∧ ran 𝐹 ∈ 𝐶) → 𝐹 ∈ V) | ||
Theorem | mptexw 7648* | Weak version of mptex 6980 that holds without ax-rep 5183. If the domain and codomain of a function given by maps-to notation are sets, the function is a set. (Contributed by Rohan Ridenour, 13-Aug-2023.) |
⊢ 𝐴 ∈ V & ⊢ 𝐶 ∈ V & ⊢ ∀𝑥 ∈ 𝐴 𝐵 ∈ 𝐶 ⇒ ⊢ (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ V | ||
Theorem | funrnex 7649 | If the domain of a function exists, so does its range. Part of Theorem 4.15(v) of [Monk1] p. 46. This theorem is derived using the Axiom of Replacement in the form of funex 6976. (Contributed by NM, 11-Nov-1995.) |
⊢ (dom 𝐹 ∈ 𝐵 → (Fun 𝐹 → ran 𝐹 ∈ V)) | ||
Theorem | zfrep6 7650* | A version of the Axiom of Replacement. Normally 𝜑 would have free variables 𝑥 and 𝑦. Axiom 6 of [Kunen] p. 12. The Separation Scheme ax-sep 5196 cannot be derived from this version and must be stated as a separate axiom in an axiom system (such as Kunen's) that uses this version in place of our ax-rep 5183. (Contributed by NM, 10-Oct-2003.) |
⊢ (∀𝑥 ∈ 𝑧 ∃!𝑦𝜑 → ∃𝑤∀𝑥 ∈ 𝑧 ∃𝑦 ∈ 𝑤 𝜑) | ||
Theorem | fornex 7651 | If the domain of an onto function exists, so does its codomain. (Contributed by NM, 23-Jul-2004.) |
⊢ (𝐴 ∈ 𝐶 → (𝐹:𝐴–onto→𝐵 → 𝐵 ∈ V)) | ||
Theorem | f1dmex 7652 | If the codomain of a one-to-one function exists, so does its domain. This theorem is equivalent to the Axiom of Replacement ax-rep 5183. (Contributed by NM, 4-Sep-2004.) |
⊢ ((𝐹:𝐴–1-1→𝐵 ∧ 𝐵 ∈ 𝐶) → 𝐴 ∈ V) | ||
Theorem | f1ovv 7653 | The range of a 1-1 onto function is a set iff its domain is a set. (Contributed by AV, 21-Mar-2019.) |
⊢ (𝐹:𝐴–1-1-onto→𝐵 → (𝐴 ∈ V ↔ 𝐵 ∈ V)) | ||
Theorem | fvclex 7654* | Existence of the class of values of a set. (Contributed by NM, 9-Nov-1995.) |
⊢ 𝐹 ∈ V ⇒ ⊢ {𝑦 ∣ ∃𝑥 𝑦 = (𝐹‘𝑥)} ∈ V | ||
Theorem | fvresex 7655* | Existence of the class of values of a restricted class. (Contributed by NM, 14-Nov-1995.) (Revised by Mario Carneiro, 11-Sep-2015.) |
⊢ 𝐴 ∈ V ⇒ ⊢ {𝑦 ∣ ∃𝑥 𝑦 = ((𝐹 ↾ 𝐴)‘𝑥)} ∈ V | ||
Theorem | abrexexg 7656* | Existence of a class abstraction of existentially restricted sets. The class 𝐵 can be thought of as an expression in 𝑥 (which is typically a free variable in the class expression substituted for 𝐵) and the class abstraction appearing in the statement as the class of values 𝐵 as 𝑥 varies through 𝐴. If the "domain" 𝐴 is a set, then the abstraction is also a set. Therefore, this statement is a kind of Replacement. This can be seen by tracing back through the path mptexg 6978, funex 6976, fnex 6974, resfunexg 6972, and funimaexg 6435. See also abrexex2g 7659. There are partial converses under additional conditions, see for instance abnexg 7472. (Contributed by NM, 3-Nov-2003.) (Proof shortened by Mario Carneiro, 31-Aug-2015.) |
⊢ (𝐴 ∈ 𝑉 → {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝑦 = 𝐵} ∈ V) | ||
Theorem | abrexex 7657* | Existence of a class abstraction of existentially restricted sets. See the comment of abrexexg 7656. See also abrexex2 7664. (Contributed by NM, 16-Oct-2003.) (Proof shortened by Mario Carneiro, 31-Aug-2015.) |
⊢ 𝐴 ∈ V ⇒ ⊢ {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝑦 = 𝐵} ∈ V | ||
Theorem | iunexg 7658* | The existence of an indexed union. 𝑥 is normally a free-variable parameter in 𝐵. (Contributed by NM, 23-Mar-2006.) |
⊢ ((𝐴 ∈ 𝑉 ∧ ∀𝑥 ∈ 𝐴 𝐵 ∈ 𝑊) → ∪ 𝑥 ∈ 𝐴 𝐵 ∈ V) | ||
Theorem | abrexex2g 7659* | Existence of an existentially restricted class abstraction. (Contributed by Jeff Madsen, 2-Sep-2009.) |
⊢ ((𝐴 ∈ 𝑉 ∧ ∀𝑥 ∈ 𝐴 {𝑦 ∣ 𝜑} ∈ 𝑊) → {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝜑} ∈ V) | ||
Theorem | opabex3d 7660* | Existence of an ordered pair abstraction, deduction version. (Contributed by Alexander van der Vekens, 19-Oct-2017.) |
⊢ (𝜑 → 𝐴 ∈ V) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → {𝑦 ∣ 𝜓} ∈ V) ⇒ ⊢ (𝜑 → {〈𝑥, 𝑦〉 ∣ (𝑥 ∈ 𝐴 ∧ 𝜓)} ∈ V) | ||
Theorem | opabex3rd 7661* | Existence of an ordered pair abstraction if the second components are elements of a set. (Contributed by AV, 17-Sep-2023.) |
⊢ (𝜑 → 𝐴 ∈ V) & ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴) → {𝑥 ∣ 𝜓} ∈ V) ⇒ ⊢ (𝜑 → {〈𝑥, 𝑦〉 ∣ (𝑦 ∈ 𝐴 ∧ 𝜓)} ∈ V) | ||
Theorem | opabex3 7662* | Existence of an ordered pair abstraction. (Contributed by Jeff Madsen, 2-Sep-2009.) |
⊢ 𝐴 ∈ V & ⊢ (𝑥 ∈ 𝐴 → {𝑦 ∣ 𝜑} ∈ V) ⇒ ⊢ {〈𝑥, 𝑦〉 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} ∈ V | ||
Theorem | iunex 7663* | The existence of an indexed union. 𝑥 is normally a free-variable parameter in the class expression substituted for 𝐵, which can be read informally as 𝐵(𝑥). (Contributed by NM, 13-Oct-2003.) |
⊢ 𝐴 ∈ V & ⊢ 𝐵 ∈ V ⇒ ⊢ ∪ 𝑥 ∈ 𝐴 𝐵 ∈ V | ||
Theorem | abrexex2 7664* | Existence of an existentially restricted class abstraction. 𝜑 normally has free-variable parameters 𝑥 and 𝑦. See also abrexex 7657. (Contributed by NM, 12-Sep-2004.) |
⊢ 𝐴 ∈ V & ⊢ {𝑦 ∣ 𝜑} ∈ V ⇒ ⊢ {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝜑} ∈ V | ||
Theorem | abexssex 7665* | Existence of a class abstraction with an existentially quantified expression. Both 𝑥 and 𝑦 can be free in 𝜑. (Contributed by NM, 29-Jul-2006.) |
⊢ 𝐴 ∈ V & ⊢ {𝑦 ∣ 𝜑} ∈ V ⇒ ⊢ {𝑦 ∣ ∃𝑥(𝑥 ⊆ 𝐴 ∧ 𝜑)} ∈ V | ||
Theorem | abexex 7666* | A condition where a class builder continues to exist after its wff is existentially quantified. (Contributed by NM, 4-Mar-2007.) |
⊢ 𝐴 ∈ V & ⊢ (𝜑 → 𝑥 ∈ 𝐴) & ⊢ {𝑦 ∣ 𝜑} ∈ V ⇒ ⊢ {𝑦 ∣ ∃𝑥𝜑} ∈ V | ||
Theorem | f1oweALT 7667* | Alternate proof of f1owe 7100, more direct since not using the isomorphism predicate, but requiring ax-un 7455. (Contributed by NM, 4-Mar-1997.) (Proof modification is discouraged.) (New usage is discouraged.) |
⊢ 𝑅 = {〈𝑥, 𝑦〉 ∣ (𝐹‘𝑥)𝑆(𝐹‘𝑦)} ⇒ ⊢ (𝐹:𝐴–1-1-onto→𝐵 → (𝑆 We 𝐵 → 𝑅 We 𝐴)) | ||
Theorem | wemoiso 7668* | Thus, there is at most one isomorphism between any two well-ordered sets. TODO: Shorten finnisoeu 9533. (Contributed by Stefan O'Rear, 12-Feb-2015.) (Revised by Mario Carneiro, 25-Jun-2015.) |
⊢ (𝑅 We 𝐴 → ∃*𝑓 𝑓 Isom 𝑅, 𝑆 (𝐴, 𝐵)) | ||
Theorem | wemoiso2 7669* | Thus, there is at most one isomorphism between any two well-ordered sets. (Contributed by Stefan O'Rear, 12-Feb-2015.) (Revised by Mario Carneiro, 25-Jun-2015.) |
⊢ (𝑆 We 𝐵 → ∃*𝑓 𝑓 Isom 𝑅, 𝑆 (𝐴, 𝐵)) | ||
Theorem | oprabexd 7670* | Existence of an operator abstraction. (Contributed by Jeff Madsen, 2-Sep-2009.) |
⊢ (𝜑 → 𝐴 ∈ V) & ⊢ (𝜑 → 𝐵 ∈ V) & ⊢ ((𝜑 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)) → ∃*𝑧𝜓) & ⊢ (𝜑 → 𝐹 = {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝜓)}) ⇒ ⊢ (𝜑 → 𝐹 ∈ V) | ||
Theorem | oprabex 7671* | Existence of an operation class abstraction. (Contributed by NM, 19-Oct-2004.) |
⊢ 𝐴 ∈ V & ⊢ 𝐵 ∈ V & ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) → ∃*𝑧𝜑) & ⊢ 𝐹 = {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝜑)} ⇒ ⊢ 𝐹 ∈ V | ||
Theorem | oprabex3 7672* | Existence of an operation class abstraction (special case). (Contributed by NM, 19-Oct-2004.) |
⊢ 𝐻 ∈ V & ⊢ 𝐹 = {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ((𝑥 ∈ (𝐻 × 𝐻) ∧ 𝑦 ∈ (𝐻 × 𝐻)) ∧ ∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = 〈𝑤, 𝑣〉 ∧ 𝑦 = 〈𝑢, 𝑓〉) ∧ 𝑧 = 𝑅))} ⇒ ⊢ 𝐹 ∈ V | ||
Theorem | oprabrexex2 7673* | Existence of an existentially restricted operation abstraction. (Contributed by Jeff Madsen, 11-Jun-2010.) |
⊢ 𝐴 ∈ V & ⊢ {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ 𝜑} ∈ V ⇒ ⊢ {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ∃𝑤 ∈ 𝐴 𝜑} ∈ V | ||
Theorem | ab2rexex 7674* | Existence of a class abstraction of existentially restricted sets. Variables 𝑥 and 𝑦 are normally free-variable parameters in the class expression substituted for 𝐶, which can be thought of as 𝐶(𝑥, 𝑦). See comments for abrexex 7657. (Contributed by NM, 20-Sep-2011.) |
⊢ 𝐴 ∈ V & ⊢ 𝐵 ∈ V ⇒ ⊢ {𝑧 ∣ ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐵 𝑧 = 𝐶} ∈ V | ||
Theorem | ab2rexex2 7675* | Existence of an existentially restricted class abstraction. 𝜑 normally has free-variable parameters 𝑥, 𝑦, and 𝑧. Compare abrexex2 7664. (Contributed by NM, 20-Sep-2011.) |
⊢ 𝐴 ∈ V & ⊢ 𝐵 ∈ V & ⊢ {𝑧 ∣ 𝜑} ∈ V ⇒ ⊢ {𝑧 ∣ ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐵 𝜑} ∈ V | ||
Theorem | xpexgALT 7676 | Alternate proof of xpexg 7467 requiring Replacement (ax-rep 5183) but not Power Set (ax-pow 5259). (Contributed by Mario Carneiro, 20-May-2013.) (Proof modification is discouraged.) (New usage is discouraged.) |
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 × 𝐵) ∈ V) | ||
Theorem | offval3 7677* | General value of (𝐹 ∘f 𝑅𝐺) with no assumptions on functionality of 𝐹 and 𝐺. (Contributed by Stefan O'Rear, 24-Jan-2015.) |
⊢ ((𝐹 ∈ 𝑉 ∧ 𝐺 ∈ 𝑊) → (𝐹 ∘f 𝑅𝐺) = (𝑥 ∈ (dom 𝐹 ∩ dom 𝐺) ↦ ((𝐹‘𝑥)𝑅(𝐺‘𝑥)))) | ||
Theorem | offres 7678 | Pointwise combination commutes with restriction. (Contributed by Stefan O'Rear, 24-Jan-2015.) |
⊢ ((𝐹 ∈ 𝑉 ∧ 𝐺 ∈ 𝑊) → ((𝐹 ∘f 𝑅𝐺) ↾ 𝐷) = ((𝐹 ↾ 𝐷) ∘f 𝑅(𝐺 ↾ 𝐷))) | ||
Theorem | ofmres 7679* | Equivalent expressions for a restriction of the function operation map. Unlike ∘f 𝑅 which is a proper class, ( ∘f 𝑅 ↾ (𝐴 × 𝐵)) can be a set by ofmresex 7680, allowing it to be used as a function or structure argument. By ofmresval 7416, the restricted operation map values are the same as the original values, allowing theorems for ∘f 𝑅 to be reused. (Contributed by NM, 20-Oct-2014.) |
⊢ ( ∘f 𝑅 ↾ (𝐴 × 𝐵)) = (𝑓 ∈ 𝐴, 𝑔 ∈ 𝐵 ↦ (𝑓 ∘f 𝑅𝑔)) | ||
Theorem | ofmresex 7680 | Existence of a restriction of the function operation map. (Contributed by NM, 20-Oct-2014.) |
⊢ (𝜑 → 𝐴 ∈ 𝑉) & ⊢ (𝜑 → 𝐵 ∈ 𝑊) ⇒ ⊢ (𝜑 → ( ∘f 𝑅 ↾ (𝐴 × 𝐵)) ∈ V) | ||
Syntax | c1st 7681 | Extend the definition of a class to include the first member an ordered pair function. |
class 1st | ||
Syntax | c2nd 7682 | Extend the definition of a class to include the second member an ordered pair function. |
class 2nd | ||
Definition | df-1st 7683 | Define a function that extracts the first member, or abscissa, of an ordered pair. Theorem op1st 7691 proves that it does this. For example, (1st ‘〈3, 4〉) = 3. Equivalent to Definition 5.13 (i) of [Monk1] p. 52 (compare op1sta 6077 and op1stb 5356). The notation is the same as Monk's. (Contributed by NM, 9-Oct-2004.) |
⊢ 1st = (𝑥 ∈ V ↦ ∪ dom {𝑥}) | ||
Definition | df-2nd 7684 | Define a function that extracts the second member, or ordinate, of an ordered pair. Theorem op2nd 7692 proves that it does this. For example, (2nd ‘〈3, 4〉) = 4. Equivalent to Definition 5.13 (ii) of [Monk1] p. 52 (compare op2nda 6080 and op2ndb 6079). The notation is the same as Monk's. (Contributed by NM, 9-Oct-2004.) |
⊢ 2nd = (𝑥 ∈ V ↦ ∪ ran {𝑥}) | ||
Theorem | 1stval 7685 | The value of the function that extracts the first member of an ordered pair. (Contributed by NM, 9-Oct-2004.) (Revised by Mario Carneiro, 8-Sep-2013.) |
⊢ (1st ‘𝐴) = ∪ dom {𝐴} | ||
Theorem | 2ndval 7686 | The value of the function that extracts the second member of an ordered pair. (Contributed by NM, 9-Oct-2004.) (Revised by Mario Carneiro, 8-Sep-2013.) |
⊢ (2nd ‘𝐴) = ∪ ran {𝐴} | ||
Theorem | 1stnpr 7687 | Value of the first-member function at non-pairs. (Contributed by Thierry Arnoux, 22-Sep-2017.) |
⊢ (¬ 𝐴 ∈ (V × V) → (1st ‘𝐴) = ∅) | ||
Theorem | 2ndnpr 7688 | Value of the second-member function at non-pairs. (Contributed by Thierry Arnoux, 22-Sep-2017.) |
⊢ (¬ 𝐴 ∈ (V × V) → (2nd ‘𝐴) = ∅) | ||
Theorem | 1st0 7689 | The value of the first-member function at the empty set. (Contributed by NM, 23-Apr-2007.) |
⊢ (1st ‘∅) = ∅ | ||
Theorem | 2nd0 7690 | The value of the second-member function at the empty set. (Contributed by NM, 23-Apr-2007.) |
⊢ (2nd ‘∅) = ∅ | ||
Theorem | op1st 7691 | Extract the first member of an ordered pair. (Contributed by NM, 5-Oct-2004.) |
⊢ 𝐴 ∈ V & ⊢ 𝐵 ∈ V ⇒ ⊢ (1st ‘〈𝐴, 𝐵〉) = 𝐴 | ||
Theorem | op2nd 7692 | Extract the second member of an ordered pair. (Contributed by NM, 5-Oct-2004.) |
⊢ 𝐴 ∈ V & ⊢ 𝐵 ∈ V ⇒ ⊢ (2nd ‘〈𝐴, 𝐵〉) = 𝐵 | ||
Theorem | op1std 7693 | Extract the first member of an ordered pair. (Contributed by Mario Carneiro, 31-Aug-2015.) |
⊢ 𝐴 ∈ V & ⊢ 𝐵 ∈ V ⇒ ⊢ (𝐶 = 〈𝐴, 𝐵〉 → (1st ‘𝐶) = 𝐴) | ||
Theorem | op2ndd 7694 | Extract the second member of an ordered pair. (Contributed by Mario Carneiro, 31-Aug-2015.) |
⊢ 𝐴 ∈ V & ⊢ 𝐵 ∈ V ⇒ ⊢ (𝐶 = 〈𝐴, 𝐵〉 → (2nd ‘𝐶) = 𝐵) | ||
Theorem | op1stg 7695 | Extract the first member of an ordered pair. (Contributed by NM, 19-Jul-2005.) |
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (1st ‘〈𝐴, 𝐵〉) = 𝐴) | ||
Theorem | op2ndg 7696 | Extract the second member of an ordered pair. (Contributed by NM, 19-Jul-2005.) |
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (2nd ‘〈𝐴, 𝐵〉) = 𝐵) | ||
Theorem | ot1stg 7697 | Extract the first member of an ordered triple. (Due to infrequent usage, it isn't worthwhile at this point to define special extractors for triples, so we reuse the ordered pair extractors for ot1stg 7697, ot2ndg 7698, ot3rdg 7699.) (Contributed by NM, 3-Apr-2015.) (Revised by Mario Carneiro, 2-May-2015.) |
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊 ∧ 𝐶 ∈ 𝑋) → (1st ‘(1st ‘〈𝐴, 𝐵, 𝐶〉)) = 𝐴) | ||
Theorem | ot2ndg 7698 | Extract the second member of an ordered triple. (See ot1stg 7697 comment.) (Contributed by NM, 3-Apr-2015.) (Revised by Mario Carneiro, 2-May-2015.) |
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊 ∧ 𝐶 ∈ 𝑋) → (2nd ‘(1st ‘〈𝐴, 𝐵, 𝐶〉)) = 𝐵) | ||
Theorem | ot3rdg 7699 | Extract the third member of an ordered triple. (See ot1stg 7697 comment.) (Contributed by NM, 3-Apr-2015.) |
⊢ (𝐶 ∈ 𝑉 → (2nd ‘〈𝐴, 𝐵, 𝐶〉) = 𝐶) | ||
Theorem | 1stval2 7700 | Alternate value of the function that extracts the first member of an ordered pair. Definition 5.13 (i) of [Monk1] p. 52. (Contributed by NM, 18-Aug-2006.) |
⊢ (𝐴 ∈ (V × V) → (1st ‘𝐴) = ∩ ∩ 𝐴) |
< Previous Next > |
Copyright terms: Public domain | < Previous Next > |