Metamath Proof Explorer


Theorem axpowndlem4

Description: Lemma for the Axiom of Power Sets with no distinct variable conditions. Usage of this theorem is discouraged because it depends on ax-13 . (Contributed by NM, 4-Jan-2002) (Proof shortened by Mario Carneiro, 10-Dec-2016) (New usage is discouraged.)

Ref Expression
Assertion axpowndlem4 ¬yy=x¬yy=z¬x=yxyxzxyyxzyx

Proof

Step Hyp Ref Expression
1 axpowndlem3 ¬x=wxwxzxwwxzwx
2 1 ax-gen w¬x=wxwxzxwwxzwx
3 nfnae y¬yy=x
4 nfnae y¬yy=z
5 3 4 nfan y¬yy=x¬yy=z
6 nfcvf ¬yy=x_yx
7 6 adantr ¬yy=x¬yy=z_yx
8 nfcvd ¬yy=x¬yy=z_yw
9 7 8 nfeqd ¬yy=x¬yy=zyx=w
10 9 nfnd ¬yy=x¬yy=zy¬x=w
11 nfnae x¬yy=x
12 nfnae x¬yy=z
13 11 12 nfan x¬yy=x¬yy=z
14 nfv w¬yy=x¬yy=z
15 nfnae z¬yy=x
16 nfnae z¬yy=z
17 15 16 nfan z¬yy=x¬yy=z
18 7 8 nfeld ¬yy=x¬yy=zyxw
19 17 18 nfexd ¬yy=x¬yy=zyzxw
20 nfcvf ¬yy=z_yz
21 20 adantl ¬yy=x¬yy=z_yz
22 7 21 nfeld ¬yy=x¬yy=zyxz
23 14 22 nfald ¬yy=x¬yy=zywxz
24 19 23 nfimd ¬yy=x¬yy=zyzxwwxz
25 13 24 nfald ¬yy=x¬yy=zyxzxwwxz
26 8 7 nfeld ¬yy=x¬yy=zywx
27 25 26 nfimd ¬yy=x¬yy=zyxzxwwxzwx
28 14 27 nfald ¬yy=x¬yy=zywxzxwwxzwx
29 13 28 nfexd ¬yy=x¬yy=zyxwxzxwwxzwx
30 10 29 nfimd ¬yy=x¬yy=zy¬x=wxwxzxwwxzwx
31 equequ2 w=yx=wx=y
32 31 notbid w=y¬x=w¬x=y
33 32 adantl ¬yy=x¬yy=zw=y¬x=w¬x=y
34 nfcvd ¬yy=x¬yy=z_xw
35 nfcvf2 ¬yy=x_xy
36 35 adantr ¬yy=x¬yy=z_xy
37 34 36 nfeqd ¬yy=x¬yy=zxw=y
38 13 37 nfan1 x¬yy=x¬yy=zw=y
39 nfcvd ¬yy=x¬yy=z_zw
40 nfcvf2 ¬yy=z_zy
41 40 adantl ¬yy=x¬yy=z_zy
42 39 41 nfeqd ¬yy=x¬yy=zzw=y
43 17 42 nfan1 z¬yy=x¬yy=zw=y
44 elequ2 w=yxwxy
45 44 adantl ¬yy=x¬yy=zw=yxwxy
46 43 45 exbid ¬yy=x¬yy=zw=yzxwzxy
47 biidd w=yxzxz
48 47 a1i ¬yy=x¬yy=zw=yxzxz
49 5 22 48 cbvald ¬yy=x¬yy=zwxzyxz
50 49 adantr ¬yy=x¬yy=zw=ywxzyxz
51 46 50 imbi12d ¬yy=x¬yy=zw=yzxwwxzzxyyxz
52 38 51 albid ¬yy=x¬yy=zw=yxzxwwxzxzxyyxz
53 elequ1 w=ywxyx
54 53 adantl ¬yy=x¬yy=zw=ywxyx
55 52 54 imbi12d ¬yy=x¬yy=zw=yxzxwwxzwxxzxyyxzyx
56 55 ex ¬yy=x¬yy=zw=yxzxwwxzwxxzxyyxzyx
57 5 27 56 cbvald ¬yy=x¬yy=zwxzxwwxzwxyxzxyyxzyx
58 13 57 exbid ¬yy=x¬yy=zxwxzxwwxzwxxyxzxyyxzyx
59 58 adantr ¬yy=x¬yy=zw=yxwxzxwwxzwxxyxzxyyxzyx
60 33 59 imbi12d ¬yy=x¬yy=zw=y¬x=wxwxzxwwxzwx¬x=yxyxzxyyxzyx
61 60 ex ¬yy=x¬yy=zw=y¬x=wxwxzxwwxzwx¬x=yxyxzxyyxzyx
62 5 30 61 cbvald ¬yy=x¬yy=zw¬x=wxwxzxwwxzwxy¬x=yxyxzxyyxzyx
63 2 62 mpbii ¬yy=x¬yy=zy¬x=yxyxzxyyxzyx
64 63 19.21bi ¬yy=x¬yy=z¬x=yxyxzxyyxzyx
65 64 ex ¬yy=x¬yy=z¬x=yxyxzxyyxzyx