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Theorem map1 7030
Description: Set exponentiation: ordinal 1 to any set is equinumerous to ordinal 1. Exercise 4.42(b) of [Mendelson] p. 255. (Contributed by NM, 17-Dec-2003.)
Assertion
Ref Expression
map1 (𝐴𝑉 → (1o𝑚 𝐴) ≈ 1o)

Proof of Theorem map1
Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 fnmap 6867 . . 3 𝑚 Fn (V × V)
2 1oex 6633 . . 3 1o ∈ V
3 elex 2815 . . 3 (𝐴𝑉𝐴 ∈ V)
4 fnovex 6061 . . 3 (( ↑𝑚 Fn (V × V) ∧ 1o ∈ V ∧ 𝐴 ∈ V) → (1o𝑚 𝐴) ∈ V)
51, 2, 3, 4mp3an12i 1378 . 2 (𝐴𝑉 → (1o𝑚 𝐴) ∈ V)
62a1i 9 . 2 (𝐴𝑉 → 1o ∈ V)
7 0ex 4221 . . 3 ∅ ∈ V
872a1i 27 . 2 (𝐴𝑉 → (𝑥 ∈ (1o𝑚 𝐴) → ∅ ∈ V))
9 p0ex 4284 . . . 4 {∅} ∈ V
10 xpexg 4846 . . . 4 ((𝐴𝑉 ∧ {∅} ∈ V) → (𝐴 × {∅}) ∈ V)
119, 10mpan2 425 . . 3 (𝐴𝑉 → (𝐴 × {∅}) ∈ V)
1211a1d 22 . 2 (𝐴𝑉 → (𝑦 ∈ 1o → (𝐴 × {∅}) ∈ V))
13 el1o 6648 . . . . 5 (𝑦 ∈ 1o𝑦 = ∅)
1413a1i 9 . . . 4 (𝐴𝑉 → (𝑦 ∈ 1o𝑦 = ∅))
15 df1o2 6639 . . . . . . . 8 1o = {∅}
1615oveq1i 6038 . . . . . . 7 (1o𝑚 𝐴) = ({∅} ↑𝑚 𝐴)
1716eleq2i 2298 . . . . . 6 (𝑥 ∈ (1o𝑚 𝐴) ↔ 𝑥 ∈ ({∅} ↑𝑚 𝐴))
18 elmapg 6873 . . . . . . 7 (({∅} ∈ V ∧ 𝐴𝑉) → (𝑥 ∈ ({∅} ↑𝑚 𝐴) ↔ 𝑥:𝐴⟶{∅}))
199, 18mpan 424 . . . . . 6 (𝐴𝑉 → (𝑥 ∈ ({∅} ↑𝑚 𝐴) ↔ 𝑥:𝐴⟶{∅}))
2017, 19bitrid 192 . . . . 5 (𝐴𝑉 → (𝑥 ∈ (1o𝑚 𝐴) ↔ 𝑥:𝐴⟶{∅}))
217fconst2 5879 . . . . 5 (𝑥:𝐴⟶{∅} ↔ 𝑥 = (𝐴 × {∅}))
2220, 21bitr2di 197 . . . 4 (𝐴𝑉 → (𝑥 = (𝐴 × {∅}) ↔ 𝑥 ∈ (1o𝑚 𝐴)))
2314, 22anbi12d 473 . . 3 (𝐴𝑉 → ((𝑦 ∈ 1o𝑥 = (𝐴 × {∅})) ↔ (𝑦 = ∅ ∧ 𝑥 ∈ (1o𝑚 𝐴))))
24 ancom 266 . . 3 ((𝑦 = ∅ ∧ 𝑥 ∈ (1o𝑚 𝐴)) ↔ (𝑥 ∈ (1o𝑚 𝐴) ∧ 𝑦 = ∅))
2523, 24bitr2di 197 . 2 (𝐴𝑉 → ((𝑥 ∈ (1o𝑚 𝐴) ∧ 𝑦 = ∅) ↔ (𝑦 ∈ 1o𝑥 = (𝐴 × {∅}))))
265, 6, 8, 12, 25en2d 6984 1 (𝐴𝑉 → (1o𝑚 𝐴) ≈ 1o)
Colors of variables: wff set class
Syntax hints:  wi 4  wa 104  wb 105   = wceq 1398  wcel 2202  Vcvv 2803  c0 3496  {csn 3673   class class class wbr 4093   × cxp 4729   Fn wfn 5328  wf 5329  (class class class)co 6028  1oc1o 6618  𝑚 cmap 6860  cen 6950
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-13 2204  ax-14 2205  ax-ext 2213  ax-sep 4212  ax-nul 4220  ax-pow 4270  ax-pr 4305  ax-un 4536  ax-setind 4641
This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-fal 1404  df-nf 1510  df-sb 1811  df-eu 2082  df-mo 2083  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2364  df-ne 2404  df-ral 2516  df-rex 2517  df-rab 2520  df-v 2805  df-sbc 3033  df-csb 3129  df-dif 3203  df-un 3205  df-in 3207  df-ss 3214  df-nul 3497  df-pw 3658  df-sn 3679  df-pr 3680  df-op 3682  df-uni 3899  df-iun 3977  df-br 4094  df-opab 4156  df-mpt 4157  df-tr 4193  df-id 4396  df-iord 4469  df-on 4471  df-suc 4474  df-xp 4737  df-rel 4738  df-cnv 4739  df-co 4740  df-dm 4741  df-rn 4742  df-res 4743  df-ima 4744  df-iota 5293  df-fun 5335  df-fn 5336  df-f 5337  df-f1 5338  df-fo 5339  df-f1o 5340  df-fv 5341  df-ov 6031  df-oprab 6032  df-mpo 6033  df-1st 6312  df-2nd 6313  df-1o 6625  df-map 6862  df-en 6953
This theorem is referenced by: (None)
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