| Step |
Hyp |
Ref |
Expression |
| 1 |
|
ax-rrecex |
|- ( ( R e. RR /\ R =/= 0 ) -> E. x e. RR ( R x. x ) = 1 ) |
| 2 |
|
sn-inelr |
|- -. _i e. RR |
| 3 |
|
simplll |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> R e. RR ) |
| 4 |
|
simplrl |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> x e. RR ) |
| 5 |
|
simplrr |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> ( R x. x ) = 1 ) |
| 6 |
3 4 5
|
remulinvcom |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> ( x x. R ) = 1 ) |
| 7 |
6
|
oveq1d |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> ( ( x x. R ) x. _i ) = ( 1 x. _i ) ) |
| 8 |
4
|
recnd |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> x e. CC ) |
| 9 |
3
|
recnd |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> R e. CC ) |
| 10 |
|
ax-icn |
|- _i e. CC |
| 11 |
10
|
a1i |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> _i e. CC ) |
| 12 |
8 9 11
|
mulassd |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> ( ( x x. R ) x. _i ) = ( x x. ( R x. _i ) ) ) |
| 13 |
|
sn-1ticom |
|- ( 1 x. _i ) = ( _i x. 1 ) |
| 14 |
|
sn-it1ei |
|- ( _i x. 1 ) = _i |
| 15 |
13 14
|
eqtri |
|- ( 1 x. _i ) = _i |
| 16 |
15
|
a1i |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> ( 1 x. _i ) = _i ) |
| 17 |
7 12 16
|
3eqtr3d |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> ( x x. ( R x. _i ) ) = _i ) |
| 18 |
|
simpr |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> ( R x. _i ) e. RR ) |
| 19 |
4 18
|
remulcld |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> ( x x. ( R x. _i ) ) e. RR ) |
| 20 |
17 19
|
eqeltrrd |
|- ( ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) /\ ( R x. _i ) e. RR ) -> _i e. RR ) |
| 21 |
20
|
ex |
|- ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) -> ( ( R x. _i ) e. RR -> _i e. RR ) ) |
| 22 |
2 21
|
mtoi |
|- ( ( ( R e. RR /\ R =/= 0 ) /\ ( x e. RR /\ ( R x. x ) = 1 ) ) -> -. ( R x. _i ) e. RR ) |
| 23 |
1 22
|
rexlimddv |
|- ( ( R e. RR /\ R =/= 0 ) -> -. ( R x. _i ) e. RR ) |
| 24 |
23
|
ex |
|- ( R e. RR -> ( R =/= 0 -> -. ( R x. _i ) e. RR ) ) |
| 25 |
24
|
necon4ad |
|- ( R e. RR -> ( ( R x. _i ) e. RR -> R = 0 ) ) |
| 26 |
|
oveq1 |
|- ( R = 0 -> ( R x. _i ) = ( 0 x. _i ) ) |
| 27 |
|
sn-0tie0 |
|- ( 0 x. _i ) = 0 |
| 28 |
|
0re |
|- 0 e. RR |
| 29 |
27 28
|
eqeltri |
|- ( 0 x. _i ) e. RR |
| 30 |
26 29
|
eqeltrdi |
|- ( R = 0 -> ( R x. _i ) e. RR ) |
| 31 |
25 30
|
impbid1 |
|- ( R e. RR -> ( ( R x. _i ) e. RR <-> R = 0 ) ) |