| Step |
Hyp |
Ref |
Expression |
| 1 |
|
simprl |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> w e. No ) |
| 2 |
|
simpl3 |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> B e. No ) |
| 3 |
1 2
|
mulscld |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> ( w x.s B ) e. No ) |
| 4 |
|
oveq1 |
|- ( ( A x.s w ) = 1s -> ( ( A x.s w ) x.s B ) = ( 1s x.s B ) ) |
| 5 |
4
|
adantl |
|- ( ( w e. No /\ ( A x.s w ) = 1s ) -> ( ( A x.s w ) x.s B ) = ( 1s x.s B ) ) |
| 6 |
5
|
adantl |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> ( ( A x.s w ) x.s B ) = ( 1s x.s B ) ) |
| 7 |
|
simpl1 |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> A e. No ) |
| 8 |
7 1 2
|
mulsassd |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> ( ( A x.s w ) x.s B ) = ( A x.s ( w x.s B ) ) ) |
| 9 |
2
|
mulslidd |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> ( 1s x.s B ) = B ) |
| 10 |
6 8 9
|
3eqtr3d |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> ( A x.s ( w x.s B ) ) = B ) |
| 11 |
|
oveq2 |
|- ( z = ( w x.s B ) -> ( A x.s z ) = ( A x.s ( w x.s B ) ) ) |
| 12 |
11
|
eqeq1d |
|- ( z = ( w x.s B ) -> ( ( A x.s z ) = B <-> ( A x.s ( w x.s B ) ) = B ) ) |
| 13 |
12
|
rspcev |
|- ( ( ( w x.s B ) e. No /\ ( A x.s ( w x.s B ) ) = B ) -> E. z e. No ( A x.s z ) = B ) |
| 14 |
3 10 13
|
syl2anc |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> E. z e. No ( A x.s z ) = B ) |
| 15 |
14
|
rexlimdvaa |
|- ( ( A e. No /\ A =/= 0s /\ B e. No ) -> ( E. w e. No ( A x.s w ) = 1s -> E. z e. No ( A x.s z ) = B ) ) |
| 16 |
15
|
imp |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ E. w e. No ( A x.s w ) = 1s ) -> E. z e. No ( A x.s z ) = B ) |
| 17 |
|
oveq2 |
|- ( x = w -> ( A x.s x ) = ( A x.s w ) ) |
| 18 |
17
|
eqeq1d |
|- ( x = w -> ( ( A x.s x ) = 1s <-> ( A x.s w ) = 1s ) ) |
| 19 |
18
|
cbvrexvw |
|- ( E. x e. No ( A x.s x ) = 1s <-> E. w e. No ( A x.s w ) = 1s ) |
| 20 |
19
|
anbi2i |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ E. x e. No ( A x.s x ) = 1s ) <-> ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ E. w e. No ( A x.s w ) = 1s ) ) |
| 21 |
|
oveq2 |
|- ( y = z -> ( A x.s y ) = ( A x.s z ) ) |
| 22 |
21
|
eqeq1d |
|- ( y = z -> ( ( A x.s y ) = B <-> ( A x.s z ) = B ) ) |
| 23 |
22
|
cbvrexvw |
|- ( E. y e. No ( A x.s y ) = B <-> E. z e. No ( A x.s z ) = B ) |
| 24 |
16 20 23
|
3imtr4i |
|- ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ E. x e. No ( A x.s x ) = 1s ) -> E. y e. No ( A x.s y ) = B ) |