Step |
Hyp |
Ref |
Expression |
1 |
|
cnvepnep |
|- ( `' _E i^i _E ) = (/) |
2 |
|
disjeq0 |
|- ( ( `' _E i^i _E ) = (/) -> ( `' _E = _E <-> ( `' _E = (/) /\ _E = (/) ) ) ) |
3 |
|
epn0 |
|- _E =/= (/) |
4 |
|
eqneqall |
|- ( _E = (/) -> ( _E =/= (/) -> `' _E =/= _E ) ) |
5 |
3 4
|
mpi |
|- ( _E = (/) -> `' _E =/= _E ) |
6 |
5
|
adantl |
|- ( ( `' _E = (/) /\ _E = (/) ) -> `' _E =/= _E ) |
7 |
6
|
a1i |
|- ( `' _E = _E -> ( ( `' _E = (/) /\ _E = (/) ) -> `' _E =/= _E ) ) |
8 |
|
neqne |
|- ( -. `' _E = _E -> `' _E =/= _E ) |
9 |
8
|
a1d |
|- ( -. `' _E = _E -> ( -. ( `' _E = (/) /\ _E = (/) ) -> `' _E =/= _E ) ) |
10 |
7 9
|
bija |
|- ( ( `' _E = _E <-> ( `' _E = (/) /\ _E = (/) ) ) -> `' _E =/= _E ) |
11 |
1 2 10
|
mp2b |
|- `' _E =/= _E |