Step |
Hyp |
Ref |
Expression |
1 |
|
inelr |
|- -. _i e. RR |
2 |
|
ax-icn |
|- _i e. CC |
3 |
2
|
a1i |
|- ( ( ( A e. RR /\ ( _i x. A ) e. RR ) /\ A =/= 0 ) -> _i e. CC ) |
4 |
|
simpll |
|- ( ( ( A e. RR /\ ( _i x. A ) e. RR ) /\ A =/= 0 ) -> A e. RR ) |
5 |
4
|
recnd |
|- ( ( ( A e. RR /\ ( _i x. A ) e. RR ) /\ A =/= 0 ) -> A e. CC ) |
6 |
|
simpr |
|- ( ( ( A e. RR /\ ( _i x. A ) e. RR ) /\ A =/= 0 ) -> A =/= 0 ) |
7 |
3 5 6
|
divcan4d |
|- ( ( ( A e. RR /\ ( _i x. A ) e. RR ) /\ A =/= 0 ) -> ( ( _i x. A ) / A ) = _i ) |
8 |
|
simplr |
|- ( ( ( A e. RR /\ ( _i x. A ) e. RR ) /\ A =/= 0 ) -> ( _i x. A ) e. RR ) |
9 |
8 4 6
|
redivcld |
|- ( ( ( A e. RR /\ ( _i x. A ) e. RR ) /\ A =/= 0 ) -> ( ( _i x. A ) / A ) e. RR ) |
10 |
7 9
|
eqeltrrd |
|- ( ( ( A e. RR /\ ( _i x. A ) e. RR ) /\ A =/= 0 ) -> _i e. RR ) |
11 |
10
|
ex |
|- ( ( A e. RR /\ ( _i x. A ) e. RR ) -> ( A =/= 0 -> _i e. RR ) ) |
12 |
11
|
necon1bd |
|- ( ( A e. RR /\ ( _i x. A ) e. RR ) -> ( -. _i e. RR -> A = 0 ) ) |
13 |
1 12
|
mpi |
|- ( ( A e. RR /\ ( _i x. A ) e. RR ) -> A = 0 ) |