| Step |
Hyp |
Ref |
Expression |
| 1 |
|
1n0 |
|- 1o =/= (/) |
| 2 |
1
|
neii |
|- -. 1o = (/) |
| 3 |
|
eqtr2 |
|- ( ( x = 1o /\ x = (/) ) -> 1o = (/) ) |
| 4 |
2 3
|
mto |
|- -. ( x = 1o /\ x = (/) ) |
| 5 |
|
1on |
|- 1o e. On |
| 6 |
|
0elon |
|- (/) e. On |
| 7 |
|
df-2o |
|- 2o = suc 1o |
| 8 |
|
df-1o |
|- 1o = suc (/) |
| 9 |
7 8
|
eqeq12i |
|- ( 2o = 1o <-> suc 1o = suc (/) ) |
| 10 |
|
suc11 |
|- ( ( 1o e. On /\ (/) e. On ) -> ( suc 1o = suc (/) <-> 1o = (/) ) ) |
| 11 |
9 10
|
bitrid |
|- ( ( 1o e. On /\ (/) e. On ) -> ( 2o = 1o <-> 1o = (/) ) ) |
| 12 |
5 6 11
|
mp2an |
|- ( 2o = 1o <-> 1o = (/) ) |
| 13 |
1 12
|
nemtbir |
|- -. 2o = 1o |
| 14 |
|
eqtr2 |
|- ( ( x = 2o /\ x = 1o ) -> 2o = 1o ) |
| 15 |
14
|
ancoms |
|- ( ( x = 1o /\ x = 2o ) -> 2o = 1o ) |
| 16 |
13 15
|
mto |
|- -. ( x = 1o /\ x = 2o ) |
| 17 |
|
nsuceq0 |
|- suc 1o =/= (/) |
| 18 |
7
|
eqeq1i |
|- ( 2o = (/) <-> suc 1o = (/) ) |
| 19 |
17 18
|
nemtbir |
|- -. 2o = (/) |
| 20 |
|
eqtr2 |
|- ( ( x = 2o /\ x = (/) ) -> 2o = (/) ) |
| 21 |
20
|
ancoms |
|- ( ( x = (/) /\ x = 2o ) -> 2o = (/) ) |
| 22 |
19 21
|
mto |
|- -. ( x = (/) /\ x = 2o ) |
| 23 |
4 16 22
|
3pm3.2ni |
|- -. ( ( x = 1o /\ x = (/) ) \/ ( x = 1o /\ x = 2o ) \/ ( x = (/) /\ x = 2o ) ) |
| 24 |
|
vex |
|- x e. _V |
| 25 |
24 24
|
brtp |
|- ( x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } x <-> ( ( x = 1o /\ x = (/) ) \/ ( x = 1o /\ x = 2o ) \/ ( x = (/) /\ x = 2o ) ) ) |
| 26 |
23 25
|
mtbir |
|- -. x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } x |
| 27 |
26
|
a1i |
|- ( x e. { 1o , 2o , (/) } -> -. x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } x ) |
| 28 |
|
vex |
|- y e. _V |
| 29 |
24 28
|
brtp |
|- ( x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } y <-> ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) ) |
| 30 |
|
vex |
|- z e. _V |
| 31 |
28 30
|
brtp |
|- ( y { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } z <-> ( ( y = 1o /\ z = (/) ) \/ ( y = 1o /\ z = 2o ) \/ ( y = (/) /\ z = 2o ) ) ) |
| 32 |
|
eqtr2 |
|- ( ( y = 1o /\ y = (/) ) -> 1o = (/) ) |
| 33 |
2 32
|
mto |
|- -. ( y = 1o /\ y = (/) ) |
| 34 |
33
|
pm2.21i |
|- ( ( y = 1o /\ y = (/) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 35 |
34
|
ad2ant2rl |
|- ( ( ( y = 1o /\ z = (/) ) /\ ( x = 1o /\ y = (/) ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 36 |
35
|
expcom |
|- ( ( x = 1o /\ y = (/) ) -> ( ( y = 1o /\ z = (/) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 37 |
34
|
ad2ant2rl |
|- ( ( ( y = 1o /\ z = 2o ) /\ ( x = 1o /\ y = (/) ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 38 |
37
|
expcom |
|- ( ( x = 1o /\ y = (/) ) -> ( ( y = 1o /\ z = 2o ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 39 |
|
3mix2 |
|- ( ( x = 1o /\ z = 2o ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 40 |
39
|
ad2ant2rl |
|- ( ( ( x = 1o /\ y = (/) ) /\ ( y = (/) /\ z = 2o ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 41 |
40
|
ex |
|- ( ( x = 1o /\ y = (/) ) -> ( ( y = (/) /\ z = 2o ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 42 |
36 38 41
|
3jaod |
|- ( ( x = 1o /\ y = (/) ) -> ( ( ( y = 1o /\ z = (/) ) \/ ( y = 1o /\ z = 2o ) \/ ( y = (/) /\ z = 2o ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 43 |
|
eqtr2 |
|- ( ( y = 2o /\ y = 1o ) -> 2o = 1o ) |
| 44 |
13 43
|
mto |
|- -. ( y = 2o /\ y = 1o ) |
| 45 |
44
|
pm2.21i |
|- ( ( y = 2o /\ y = 1o ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 46 |
45
|
ad2ant2lr |
|- ( ( ( x = 1o /\ y = 2o ) /\ ( y = 1o /\ z = (/) ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 47 |
46
|
ex |
|- ( ( x = 1o /\ y = 2o ) -> ( ( y = 1o /\ z = (/) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 48 |
45
|
ad2ant2lr |
|- ( ( ( x = 1o /\ y = 2o ) /\ ( y = 1o /\ z = 2o ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 49 |
48
|
ex |
|- ( ( x = 1o /\ y = 2o ) -> ( ( y = 1o /\ z = 2o ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 50 |
|
eqtr2 |
|- ( ( y = 2o /\ y = (/) ) -> 2o = (/) ) |
| 51 |
19 50
|
mto |
|- -. ( y = 2o /\ y = (/) ) |
| 52 |
51
|
pm2.21i |
|- ( ( y = 2o /\ y = (/) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 53 |
52
|
ad2ant2lr |
|- ( ( ( x = 1o /\ y = 2o ) /\ ( y = (/) /\ z = 2o ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 54 |
53
|
ex |
|- ( ( x = 1o /\ y = 2o ) -> ( ( y = (/) /\ z = 2o ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 55 |
47 49 54
|
3jaod |
|- ( ( x = 1o /\ y = 2o ) -> ( ( ( y = 1o /\ z = (/) ) \/ ( y = 1o /\ z = 2o ) \/ ( y = (/) /\ z = 2o ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 56 |
45
|
ad2ant2lr |
|- ( ( ( x = (/) /\ y = 2o ) /\ ( y = 1o /\ z = (/) ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 57 |
56
|
ex |
|- ( ( x = (/) /\ y = 2o ) -> ( ( y = 1o /\ z = (/) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 58 |
45
|
ad2ant2lr |
|- ( ( ( x = (/) /\ y = 2o ) /\ ( y = 1o /\ z = 2o ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 59 |
58
|
ex |
|- ( ( x = (/) /\ y = 2o ) -> ( ( y = 1o /\ z = 2o ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 60 |
52
|
ad2ant2lr |
|- ( ( ( x = (/) /\ y = 2o ) /\ ( y = (/) /\ z = 2o ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 61 |
60
|
ex |
|- ( ( x = (/) /\ y = 2o ) -> ( ( y = (/) /\ z = 2o ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 62 |
57 59 61
|
3jaod |
|- ( ( x = (/) /\ y = 2o ) -> ( ( ( y = 1o /\ z = (/) ) \/ ( y = 1o /\ z = 2o ) \/ ( y = (/) /\ z = 2o ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 63 |
42 55 62
|
3jaoi |
|- ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) -> ( ( ( y = 1o /\ z = (/) ) \/ ( y = 1o /\ z = 2o ) \/ ( y = (/) /\ z = 2o ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) ) |
| 64 |
63
|
imp |
|- ( ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) /\ ( ( y = 1o /\ z = (/) ) \/ ( y = 1o /\ z = 2o ) \/ ( y = (/) /\ z = 2o ) ) ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 65 |
29 31 64
|
syl2anb |
|- ( ( x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } y /\ y { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } z ) -> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 66 |
24 30
|
brtp |
|- ( x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } z <-> ( ( x = 1o /\ z = (/) ) \/ ( x = 1o /\ z = 2o ) \/ ( x = (/) /\ z = 2o ) ) ) |
| 67 |
65 66
|
sylibr |
|- ( ( x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } y /\ y { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } z ) -> x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } z ) |
| 68 |
67
|
a1i |
|- ( ( x e. { 1o , 2o , (/) } /\ y e. { 1o , 2o , (/) } /\ z e. { 1o , 2o , (/) } ) -> ( ( x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } y /\ y { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } z ) -> x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } z ) ) |
| 69 |
24
|
eltp |
|- ( x e. { 1o , 2o , (/) } <-> ( x = 1o \/ x = 2o \/ x = (/) ) ) |
| 70 |
28
|
eltp |
|- ( y e. { 1o , 2o , (/) } <-> ( y = 1o \/ y = 2o \/ y = (/) ) ) |
| 71 |
|
eqtr3 |
|- ( ( x = 1o /\ y = 1o ) -> x = y ) |
| 72 |
71
|
3mix2d |
|- ( ( x = 1o /\ y = 1o ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 73 |
72
|
ex |
|- ( x = 1o -> ( y = 1o -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 74 |
|
3mix2 |
|- ( ( x = 1o /\ y = 2o ) -> ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) ) |
| 75 |
74
|
3mix1d |
|- ( ( x = 1o /\ y = 2o ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 76 |
75
|
ex |
|- ( x = 1o -> ( y = 2o -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 77 |
|
3mix1 |
|- ( ( x = 1o /\ y = (/) ) -> ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) ) |
| 78 |
77
|
3mix1d |
|- ( ( x = 1o /\ y = (/) ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 79 |
78
|
ex |
|- ( x = 1o -> ( y = (/) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 80 |
73 76 79
|
3jaod |
|- ( x = 1o -> ( ( y = 1o \/ y = 2o \/ y = (/) ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 81 |
|
3mix2 |
|- ( ( y = 1o /\ x = 2o ) -> ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) |
| 82 |
81
|
3mix3d |
|- ( ( y = 1o /\ x = 2o ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 83 |
82
|
expcom |
|- ( x = 2o -> ( y = 1o -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 84 |
|
eqtr3 |
|- ( ( x = 2o /\ y = 2o ) -> x = y ) |
| 85 |
84
|
3mix2d |
|- ( ( x = 2o /\ y = 2o ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 86 |
85
|
ex |
|- ( x = 2o -> ( y = 2o -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 87 |
|
3mix3 |
|- ( ( y = (/) /\ x = 2o ) -> ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) |
| 88 |
87
|
3mix3d |
|- ( ( y = (/) /\ x = 2o ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 89 |
88
|
expcom |
|- ( x = 2o -> ( y = (/) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 90 |
83 86 89
|
3jaod |
|- ( x = 2o -> ( ( y = 1o \/ y = 2o \/ y = (/) ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 91 |
|
3mix1 |
|- ( ( y = 1o /\ x = (/) ) -> ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) |
| 92 |
91
|
3mix3d |
|- ( ( y = 1o /\ x = (/) ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 93 |
92
|
expcom |
|- ( x = (/) -> ( y = 1o -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 94 |
|
3mix3 |
|- ( ( x = (/) /\ y = 2o ) -> ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) ) |
| 95 |
94
|
3mix1d |
|- ( ( x = (/) /\ y = 2o ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 96 |
95
|
ex |
|- ( x = (/) -> ( y = 2o -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 97 |
|
eqtr3 |
|- ( ( x = (/) /\ y = (/) ) -> x = y ) |
| 98 |
97
|
3mix2d |
|- ( ( x = (/) /\ y = (/) ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 99 |
98
|
ex |
|- ( x = (/) -> ( y = (/) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 100 |
93 96 99
|
3jaod |
|- ( x = (/) -> ( ( y = 1o \/ y = 2o \/ y = (/) ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 101 |
80 90 100
|
3jaoi |
|- ( ( x = 1o \/ x = 2o \/ x = (/) ) -> ( ( y = 1o \/ y = 2o \/ y = (/) ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) ) |
| 102 |
101
|
imp |
|- ( ( ( x = 1o \/ x = 2o \/ x = (/) ) /\ ( y = 1o \/ y = 2o \/ y = (/) ) ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 103 |
69 70 102
|
syl2anb |
|- ( ( x e. { 1o , 2o , (/) } /\ y e. { 1o , 2o , (/) } ) -> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 104 |
|
biid |
|- ( x = y <-> x = y ) |
| 105 |
28 24
|
brtp |
|- ( y { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } x <-> ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) |
| 106 |
29 104 105
|
3orbi123i |
|- ( ( x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } y \/ x = y \/ y { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } x ) <-> ( ( ( x = 1o /\ y = (/) ) \/ ( x = 1o /\ y = 2o ) \/ ( x = (/) /\ y = 2o ) ) \/ x = y \/ ( ( y = 1o /\ x = (/) ) \/ ( y = 1o /\ x = 2o ) \/ ( y = (/) /\ x = 2o ) ) ) ) |
| 107 |
103 106
|
sylibr |
|- ( ( x e. { 1o , 2o , (/) } /\ y e. { 1o , 2o , (/) } ) -> ( x { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } y \/ x = y \/ y { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } x ) ) |
| 108 |
27 68 107
|
issoi |
|- { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } Or { 1o , 2o , (/) } |
| 109 |
|
df-tp |
|- { 1o , 2o , (/) } = ( { 1o , 2o } u. { (/) } ) |
| 110 |
|
soeq2 |
|- ( { 1o , 2o , (/) } = ( { 1o , 2o } u. { (/) } ) -> ( { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } Or { 1o , 2o , (/) } <-> { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } Or ( { 1o , 2o } u. { (/) } ) ) ) |
| 111 |
109 110
|
ax-mp |
|- ( { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } Or { 1o , 2o , (/) } <-> { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } Or ( { 1o , 2o } u. { (/) } ) ) |
| 112 |
108 111
|
mpbi |
|- { <. 1o , (/) >. , <. 1o , 2o >. , <. (/) , 2o >. } Or ( { 1o , 2o } u. { (/) } ) |