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Theorem axregndlem2 4935
Description: Lemma for the Axiom of Regularity with no distinct variable conditions.
Assertion
Ref Expression
axregndlem2 (xy → ∃x(xy ⋀ ∀z(zx → ¬ zy)))
Distinct variable group:   y,z

Proof of Theorem axregndlem2
StepHypRef Expression
1 axreg 4574 . . . . . 6 (wy → ∃w(wy ⋀ ∀z(zw → ¬ zy)))
21ax-gen 961 . . . . 5 w(wy → ∃w(wy ⋀ ∀z(zw → ¬ zy)))
3 hbnae 1145 . . . . . . 7 (¬ ∀x x = y → ∀x ¬ ∀x x = y)
4 hbnae 1145 . . . . . . 7 (¬ ∀x x = z → ∀x ¬ ∀x x = z)
53, 4hban 1007 . . . . . 6 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → ∀x(¬ ∀x x = y ⋀ ¬ ∀x x = z))
6 dveel2 1355 . . . . . . . 8 (¬ ∀x x = y → (wy → ∀x wy))
76adantr 389 . . . . . . 7 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → (wy → ∀x wy))
8 ax-17 969 . . . . . . . 8 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → ∀w(¬ ∀x x = y ⋀ ¬ ∀x x = z))
9 hbnae 1145 . . . . . . . . . . 11 (¬ ∀x x = y → ∀z ¬ ∀x x = y)
10 hbnae 1145 . . . . . . . . . . 11 (¬ ∀x x = z → ∀z ¬ ∀x x = z)
119, 10hban 1007 . . . . . . . . . 10 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → ∀z(¬ ∀x x = y ⋀ ¬ ∀x x = z))
12 dveel1 1354 . . . . . . . . . . . 12 (¬ ∀x x = z → (zw → ∀x zw))
1312adantl 388 . . . . . . . . . . 11 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → (zw → ∀x zw))
14 ax-15 1358 . . . . . . . . . . . . 13 (¬ ∀x x = z → (¬ ∀x x = y → (zy → ∀x zy)))
1514impcom 351 . . . . . . . . . . . 12 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → (zy → ∀x zy))
165, 15hbnd 1107 . . . . . . . . . . 11 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → (¬ zy → ∀x ¬ zy))
175, 13, 16hbimd 1108 . . . . . . . . . 10 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → ((zw → ¬ zy) → ∀x(zw → ¬ zy)))
1811, 17hbald 1111 . . . . . . . . 9 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → (∀z(zw → ¬ zy) → ∀xz(zw → ¬ zy)))
197, 18hband 1109 . . . . . . . 8 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → ((wy ⋀ ∀z(zw → ¬ zy)) → ∀x(wy ⋀ ∀z(zw → ¬ zy))))
208, 19hbexd 1112 . . . . . . 7 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → (∃w(wy ⋀ ∀z(zw → ¬ zy)) → ∀xw(wy ⋀ ∀z(zw → ¬ zy))))
215, 7, 20hbimd 1108 . . . . . 6 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → ((wy → ∃w(wy ⋀ ∀z(zw → ¬ zy))) → ∀x(wy → ∃w(wy ⋀ ∀z(zw → ¬ zy)))))
22 elequ1 1134 . . . . . . . . 9 (w = x → (wyxy))
2322adantl 388 . . . . . . . 8 (((¬ ∀x x = y ⋀ ¬ ∀x x = z) ⋀ w = x) → (wyxy))
2422adantl 388 . . . . . . . . . . . . 13 ((¬ ∀x x = zw = x) → (wyxy))
25 nd5 4922 . . . . . . . . . . . . . . 15 (¬ ∀x x = z → (w = x → ∀z w = x))
2625imdistani 443 . . . . . . . . . . . . . 14 ((¬ ∀x x = zw = x) → (¬ ∀x x = z ⋀ ∀z w = x))
27 hba1 1001 . . . . . . . . . . . . . . . 16 (∀z w = x → ∀zz w = x)
2810, 27hban 1007 . . . . . . . . . . . . . . 15 ((¬ ∀x x = z ⋀ ∀z w = x) → ∀z(¬ ∀x x = z ⋀ ∀z w = x))
29 elequ2 1135 . . . . . . . . . . . . . . . . . 18 (w = x → (zwzx))
3029imbi1d 612 . . . . . . . . . . . . . . . . 17 (w = x → ((zw → ¬ zy) ↔ (zx → ¬ zy)))
3130a4s 982 . . . . . . . . . . . . . . . 16 (∀z w = x → ((zw → ¬ zy) ↔ (zx → ¬ zy)))
3231adantl 388 . . . . . . . . . . . . . . 15 ((¬ ∀x x = z ⋀ ∀z w = x) → ((zw → ¬ zy) ↔ (zx → ¬ zy)))
3328, 32albid 1102 . . . . . . . . . . . . . 14 ((¬ ∀x x = z ⋀ ∀z w = x) → (∀z(zw → ¬ zy) ↔ ∀z(zx → ¬ zy)))
3426, 33syl 10 . . . . . . . . . . . . 13 ((¬ ∀x x = zw = x) → (∀z(zw → ¬ zy) ↔ ∀z(zx → ¬ zy)))
3524, 34anbi12d 627 . . . . . . . . . . . 12 ((¬ ∀x x = zw = x) → ((wy ⋀ ∀z(zw → ¬ zy)) ↔ (xy ⋀ ∀z(zx → ¬ zy))))
3635ex 373 . . . . . . . . . . 11 (¬ ∀x x = z → (w = x → ((wy ⋀ ∀z(zw → ¬ zy)) ↔ (xy ⋀ ∀z(zx → ¬ zy)))))
3736adantl 388 . . . . . . . . . 10 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → (w = x → ((wy ⋀ ∀z(zw → ¬ zy)) ↔ (xy ⋀ ∀z(zx → ¬ zy)))))
385, 19, 37cbvexd 1319 . . . . . . . . 9 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → (∃w(wy ⋀ ∀z(zw → ¬ zy)) ↔ ∃x(xy ⋀ ∀z(zx → ¬ zy))))
3938adantr 389 . . . . . . . 8 (((¬ ∀x x = y ⋀ ¬ ∀x x = z) ⋀ w = x) → (∃w(wy ⋀ ∀z(zw → ¬ zy)) ↔ ∃x(xy ⋀ ∀z(zx → ¬ zy))))
4023, 39imbi12d 625 . . . . . . 7 (((¬ ∀x x = y ⋀ ¬ ∀x x = z) ⋀ w = x) → ((wy → ∃w(wy ⋀ ∀z(zw → ¬ zy))) ↔ (xy → ∃x(xy ⋀ ∀z(zx → ¬ zy)))))
4140ex 373 . . . . . 6 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → (w = x → ((wy → ∃w(wy ⋀ ∀z(zw → ¬ zy))) ↔ (xy → ∃x(xy ⋀ ∀z(zx → ¬ zy))))))
425, 21, 41cbvald 1318 . . . . 5 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → (∀w(wy → ∃w(wy ⋀ ∀z(zw → ¬ zy))) ↔ ∀x(xy → ∃x(xy ⋀ ∀z(zx → ¬ zy)))))
432, 42mpbii 193 . . . 4 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → ∀x(xy → ∃x(xy ⋀ ∀z(zx → ¬ zy))))
444319.21bi 1058 . . 3 ((¬ ∀x x = y ⋀ ¬ ∀x x = z) → (xy → ∃x(xy ⋀ ∀z(zx → ¬ zy))))
4544ex 373 . 2 (¬ ∀x x = y → (¬ ∀x x = z → (xy → ∃x(xy ⋀ ∀z(zx → ¬ zy)))))
46 elirrv 4578 . . . . 5 ¬ xx
47 elequ2 1135 . . . . 5 (x = y → (xxxy))
4846, 47mtbii 715 . . . 4 (x = y → ¬ xy)
4948a4s 982 . . 3 (∀x x = y → ¬ xy)
5049pm2.21d 78 . 2 (∀x x = y → (xy → ∃x(xy ⋀ ∀z(zx → ¬ zy))))
51 axregndlem1 4934 . 2 (∀x x = z → (xy → ∃x(xy ⋀ ∀z(zx → ¬ zy))))
5245, 50, 51pm2.61ii 130 1 (xy → ∃x(xy ⋀ ∀z(zx → ¬ zy)))
Colors of variables: wff set class
Syntax hints:  ¬ wn 2   → wi 3   ↔ wb 146   ⋀ wa 223  ∀wal 952   = wceq 954   ∈ wcel 956  ∃wex 978
This theorem is referenced by:  axregnd 4936
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 960  ax-gen 961  ax-8 962  ax-10 964  ax-11 965  ax-12 966  ax-13 967  ax-14 968  ax-17 969  ax-4 971  ax-5o 973  ax-6o 976  ax-9o 1121  ax-10o 1138  ax-16 1208  ax-11o 1216  ax-15 1358  ax-ext 1457  ax-sep 2698  ax-pow 2737  ax-reg 4573
This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225  df-ex 979  df-sb 1170  df-eu 1380  df-mo 1381  df-clab 1462  df-cleq 1467  df-clel 1470  df-ne 1584  df-ral 1646  df-rex 1647  df-v 1808  df-dif 2045  df-un 2046  df-in 2047  df-ss 2049  df-nul 2277  df-pw 2398  df-sn 2408  df-pr 2409
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