Step |
Hyp |
Ref |
Expression |
1 |
|
elrlocbasi.x |
|- ( ph -> X e. ( ( B X. S ) /. .~ ) ) |
2 |
|
simp-4r |
|- ( ( ( ( ( ( ph /\ z e. ( B X. S ) ) /\ X = [ z ] .~ ) /\ a e. B ) /\ b e. S ) /\ z = <. a , b >. ) -> X = [ z ] .~ ) |
3 |
|
simpr |
|- ( ( ( ( ( ( ph /\ z e. ( B X. S ) ) /\ X = [ z ] .~ ) /\ a e. B ) /\ b e. S ) /\ z = <. a , b >. ) -> z = <. a , b >. ) |
4 |
3
|
eceq1d |
|- ( ( ( ( ( ( ph /\ z e. ( B X. S ) ) /\ X = [ z ] .~ ) /\ a e. B ) /\ b e. S ) /\ z = <. a , b >. ) -> [ z ] .~ = [ <. a , b >. ] .~ ) |
5 |
2 4
|
eqtrd |
|- ( ( ( ( ( ( ph /\ z e. ( B X. S ) ) /\ X = [ z ] .~ ) /\ a e. B ) /\ b e. S ) /\ z = <. a , b >. ) -> X = [ <. a , b >. ] .~ ) |
6 |
|
elxp2 |
|- ( z e. ( B X. S ) <-> E. a e. B E. b e. S z = <. a , b >. ) |
7 |
6
|
biimpi |
|- ( z e. ( B X. S ) -> E. a e. B E. b e. S z = <. a , b >. ) |
8 |
7
|
ad2antlr |
|- ( ( ( ph /\ z e. ( B X. S ) ) /\ X = [ z ] .~ ) -> E. a e. B E. b e. S z = <. a , b >. ) |
9 |
5 8
|
reximddv2 |
|- ( ( ( ph /\ z e. ( B X. S ) ) /\ X = [ z ] .~ ) -> E. a e. B E. b e. S X = [ <. a , b >. ] .~ ) |
10 |
|
elqsi |
|- ( X e. ( ( B X. S ) /. .~ ) -> E. z e. ( B X. S ) X = [ z ] .~ ) |
11 |
1 10
|
syl |
|- ( ph -> E. z e. ( B X. S ) X = [ z ] .~ ) |
12 |
9 11
|
r19.29a |
|- ( ph -> E. a e. B E. b e. S X = [ <. a , b >. ] .~ ) |