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Mirrors > Home > MPE Home > Th. List > tz9.1 | Structured version Visualization version GIF version |
Description: Every set has a
transitive closure (the smallest transitive extension).
Theorem 9.1 of [TakeutiZaring] p.
73. See trcl 8777 for an explicit
expression for the transitive closure. Apparently open problems are
whether this theorem can be proved without the Axiom of Infinity; if
not, then whether it implies Infinity; and if not, what is the
"property" that Infinity has that the other axioms don't have
that is
weaker than Infinity itself?
(Added 22-Mar-2011) The following article seems to answer the first question, that it can't be proved without Infinity, in the affirmative: Mancini, Antonella and Zambella, Domenico (2001). "A note on recursive models of set theories." Notre Dame Journal of Formal Logic, 42(2):109-115. (Thanks to Scott Fenton.) (Contributed by NM, 15-Sep-2003.) |
Ref | Expression |
---|---|
tz9.1.1 | ⊢ 𝐴 ∈ V |
Ref | Expression |
---|---|
tz9.1 | ⊢ ∃𝑥(𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | tz9.1.1 | . . 3 ⊢ 𝐴 ∈ V | |
2 | eqid 2760 | . . 3 ⊢ (rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω) = (rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω) | |
3 | eqid 2760 | . . 3 ⊢ ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) = ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) | |
4 | 1, 2, 3 | trcl 8777 | . 2 ⊢ (𝐴 ⊆ ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ∧ Tr ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ∧ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ⊆ 𝑦)) |
5 | omex 8713 | . . . 4 ⊢ ω ∈ V | |
6 | fvex 6362 | . . . 4 ⊢ ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ∈ V | |
7 | 5, 6 | iunex 7312 | . . 3 ⊢ ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ∈ V |
8 | sseq2 3768 | . . . 4 ⊢ (𝑥 = ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) → (𝐴 ⊆ 𝑥 ↔ 𝐴 ⊆ ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧))) | |
9 | treq 4910 | . . . 4 ⊢ (𝑥 = ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) → (Tr 𝑥 ↔ Tr ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧))) | |
10 | sseq1 3767 | . . . . . 6 ⊢ (𝑥 = ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) → (𝑥 ⊆ 𝑦 ↔ ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ⊆ 𝑦)) | |
11 | 10 | imbi2d 329 | . . . . 5 ⊢ (𝑥 = ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) → (((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦) ↔ ((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ⊆ 𝑦))) |
12 | 11 | albidv 1998 | . . . 4 ⊢ (𝑥 = ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) → (∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦) ↔ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ⊆ 𝑦))) |
13 | 8, 9, 12 | 3anbi123d 1548 | . . 3 ⊢ (𝑥 = ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) → ((𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) ↔ (𝐴 ⊆ ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ∧ Tr ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ∧ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ⊆ 𝑦)))) |
14 | 7, 13 | spcev 3440 | . 2 ⊢ ((𝐴 ⊆ ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ∧ Tr ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ∧ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → ∪ 𝑧 ∈ ω ((rec((𝑤 ∈ V ↦ (𝑤 ∪ ∪ 𝑤)), 𝐴) ↾ ω)‘𝑧) ⊆ 𝑦)) → ∃𝑥(𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦))) |
15 | 4, 14 | ax-mp 5 | 1 ⊢ ∃𝑥(𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 383 ∧ w3a 1072 ∀wal 1630 = wceq 1632 ∃wex 1853 ∈ wcel 2139 Vcvv 3340 ∪ cun 3713 ⊆ wss 3715 ∪ cuni 4588 ∪ ciun 4672 ↦ cmpt 4881 Tr wtr 4904 ↾ cres 5268 ‘cfv 6049 ωcom 7230 reccrdg 7674 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1871 ax-4 1886 ax-5 1988 ax-6 2054 ax-7 2090 ax-8 2141 ax-9 2148 ax-10 2168 ax-11 2183 ax-12 2196 ax-13 2391 ax-ext 2740 ax-rep 4923 ax-sep 4933 ax-nul 4941 ax-pow 4992 ax-pr 5055 ax-un 7114 ax-inf2 8711 |
This theorem depends on definitions: df-bi 197 df-or 384 df-an 385 df-3or 1073 df-3an 1074 df-tru 1635 df-ex 1854 df-nf 1859 df-sb 2047 df-eu 2611 df-mo 2612 df-clab 2747 df-cleq 2753 df-clel 2756 df-nfc 2891 df-ne 2933 df-ral 3055 df-rex 3056 df-reu 3057 df-rab 3059 df-v 3342 df-sbc 3577 df-csb 3675 df-dif 3718 df-un 3720 df-in 3722 df-ss 3729 df-pss 3731 df-nul 4059 df-if 4231 df-pw 4304 df-sn 4322 df-pr 4324 df-tp 4326 df-op 4328 df-uni 4589 df-iun 4674 df-br 4805 df-opab 4865 df-mpt 4882 df-tr 4905 df-id 5174 df-eprel 5179 df-po 5187 df-so 5188 df-fr 5225 df-we 5227 df-xp 5272 df-rel 5273 df-cnv 5274 df-co 5275 df-dm 5276 df-rn 5277 df-res 5278 df-ima 5279 df-pred 5841 df-ord 5887 df-on 5888 df-lim 5889 df-suc 5890 df-iota 6012 df-fun 6051 df-fn 6052 df-f 6053 df-f1 6054 df-fo 6055 df-f1o 6056 df-fv 6057 df-om 7231 df-wrecs 7576 df-recs 7637 df-rdg 7675 |
This theorem is referenced by: epfrs 8780 |
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