| Step |
Hyp |
Ref |
Expression |
| 1 |
|
elre0re |
|- ( A e. RR -> 0 e. RR ) |
| 2 |
1
|
recnd |
|- ( A e. RR -> 0 e. CC ) |
| 3 |
1 1
|
readdcld |
|- ( A e. RR -> ( 0 + 0 ) e. RR ) |
| 4 |
|
rernegcl |
|- ( ( 0 + 0 ) e. RR -> ( 0 -R ( 0 + 0 ) ) e. RR ) |
| 5 |
3 4
|
syl |
|- ( A e. RR -> ( 0 -R ( 0 + 0 ) ) e. RR ) |
| 6 |
5
|
recnd |
|- ( A e. RR -> ( 0 -R ( 0 + 0 ) ) e. CC ) |
| 7 |
2 2 6
|
addassd |
|- ( A e. RR -> ( ( 0 + 0 ) + ( 0 -R ( 0 + 0 ) ) ) = ( 0 + ( 0 + ( 0 -R ( 0 + 0 ) ) ) ) ) |
| 8 |
|
renegid |
|- ( ( 0 + 0 ) e. RR -> ( ( 0 + 0 ) + ( 0 -R ( 0 + 0 ) ) ) = 0 ) |
| 9 |
3 8
|
syl |
|- ( A e. RR -> ( ( 0 + 0 ) + ( 0 -R ( 0 + 0 ) ) ) = 0 ) |
| 10 |
7 9
|
eqtr3d |
|- ( A e. RR -> ( 0 + ( 0 + ( 0 -R ( 0 + 0 ) ) ) ) = 0 ) |
| 11 |
1 5
|
readdcld |
|- ( A e. RR -> ( 0 + ( 0 -R ( 0 + 0 ) ) ) e. RR ) |
| 12 |
|
renegadd |
|- ( ( 0 e. RR /\ ( 0 + ( 0 -R ( 0 + 0 ) ) ) e. RR ) -> ( ( 0 -R 0 ) = ( 0 + ( 0 -R ( 0 + 0 ) ) ) <-> ( 0 + ( 0 + ( 0 -R ( 0 + 0 ) ) ) ) = 0 ) ) |
| 13 |
1 11 12
|
syl2anc |
|- ( A e. RR -> ( ( 0 -R 0 ) = ( 0 + ( 0 -R ( 0 + 0 ) ) ) <-> ( 0 + ( 0 + ( 0 -R ( 0 + 0 ) ) ) ) = 0 ) ) |
| 14 |
10 13
|
mpbird |
|- ( A e. RR -> ( 0 -R 0 ) = ( 0 + ( 0 -R ( 0 + 0 ) ) ) ) |
| 15 |
14
|
eqcomd |
|- ( A e. RR -> ( 0 + ( 0 -R ( 0 + 0 ) ) ) = ( 0 -R 0 ) ) |