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Theorem ordsucunielexmid 4198
 Description: The converse of sucunielr 4183 (where B is an ordinal) implies excluded middle. (Contributed by Jim Kingdon, 2-Aug-2019.)
Hypothesis
Ref Expression
ordsucunielexmid.1 x On y On (x y → suc x y)
Assertion
Ref Expression
ordsucunielexmid (φ ¬ φ)
Distinct variable group:   φ,x,y

Proof of Theorem ordsucunielexmid
Dummy variables 𝑎 𝑏 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 eloni 4059 . . . . . . . 8 (𝑏 On → Ord 𝑏)
2 ordtr 4062 . . . . . . . 8 (Ord 𝑏 → Tr 𝑏)
31, 2syl 14 . . . . . . 7 (𝑏 On → Tr 𝑏)
4 vex 2537 . . . . . . . 8 𝑏 V
54unisuc 4097 . . . . . . 7 (Tr 𝑏 suc 𝑏 = 𝑏)
63, 5sylib 127 . . . . . 6 (𝑏 On → suc 𝑏 = 𝑏)
76eleq2d 2090 . . . . 5 (𝑏 On → (𝑎 suc 𝑏𝑎 𝑏))
87adantl 262 . . . 4 ((𝑎 On 𝑏 On) → (𝑎 suc 𝑏𝑎 𝑏))
9 suceloni 4175 . . . . 5 (𝑏 On → suc 𝑏 On)
10 ordsucunielexmid.1 . . . . . 6 x On y On (x y → suc x y)
11 eleq1 2083 . . . . . . . 8 (x = 𝑎 → (x y𝑎 y))
12 suceq 4086 . . . . . . . . 9 (x = 𝑎 → suc x = suc 𝑎)
1312eleq1d 2089 . . . . . . . 8 (x = 𝑎 → (suc x y ↔ suc 𝑎 y))
1411, 13imbi12d 223 . . . . . . 7 (x = 𝑎 → ((x y → suc x y) ↔ (𝑎 y → suc 𝑎 y)))
15 unieq 3562 . . . . . . . . 9 (y = suc 𝑏 y = suc 𝑏)
1615eleq2d 2090 . . . . . . . 8 (y = suc 𝑏 → (𝑎 y𝑎 suc 𝑏))
17 eleq2 2084 . . . . . . . 8 (y = suc 𝑏 → (suc 𝑎 y ↔ suc 𝑎 suc 𝑏))
1816, 17imbi12d 223 . . . . . . 7 (y = suc 𝑏 → ((𝑎 y → suc 𝑎 y) ↔ (𝑎 suc 𝑏 → suc 𝑎 suc 𝑏)))
1914, 18rspc2va 2639 . . . . . 6 (((𝑎 On suc 𝑏 On) x On y On (x y → suc x y)) → (𝑎 suc 𝑏 → suc 𝑎 suc 𝑏))
2010, 19mpan2 403 . . . . 5 ((𝑎 On suc 𝑏 On) → (𝑎 suc 𝑏 → suc 𝑎 suc 𝑏))
219, 20sylan2 270 . . . 4 ((𝑎 On 𝑏 On) → (𝑎 suc 𝑏 → suc 𝑎 suc 𝑏))
228, 21sylbird 159 . . 3 ((𝑎 On 𝑏 On) → (𝑎 𝑏 → suc 𝑎 suc 𝑏))
2322rgen2a 2352 . 2 𝑎 On 𝑏 On (𝑎 𝑏 → suc 𝑎 suc 𝑏)
2423onsucelsucexmid 4197 1 (φ ¬ φ)
 Colors of variables: wff set class Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 97   ↔ wb 98   ∨ wo 616   = wceq 1228   ∈ wcel 1375  ∀wral 2283  ∪ cuni 3553  Tr wtr 3827  Ord word 4046  Oncon0 4047  suc csuc 4049 This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-in1 532  ax-in2 533  ax-io 617  ax-5 1316  ax-7 1317  ax-gen 1318  ax-ie1 1364  ax-ie2 1365  ax-8 1377  ax-10 1378  ax-11 1379  ax-i12 1380  ax-bnd 1381  ax-4 1382  ax-13 1386  ax-14 1387  ax-17 1401  ax-i9 1405  ax-ial 1410  ax-i5r 1411  ax-ext 2005  ax-sep 3848  ax-nul 3856  ax-pow 3900  ax-pr 3917  ax-un 4118 This theorem depends on definitions:  df-bi 110  df-3an 875  df-tru 1231  df-nf 1330  df-sb 1629  df-clab 2010  df-cleq 2016  df-clel 2019  df-nfc 2150  df-ne 2189  df-ral 2288  df-rex 2289  df-rab 2292  df-v 2536  df-dif 2896  df-un 2898  df-in 2900  df-ss 2907  df-nul 3201  df-pw 3335  df-sn 3355  df-pr 3356  df-uni 3554  df-tr 3828  df-iord 4050  df-on 4052  df-suc 4055 This theorem is referenced by: (None)
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