This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Lemma 1 for or2expropbi and ich2exprop . (Contributed by AV, 16-Jul-2023)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | or2expropbilem1 | |- ( ( A e. X /\ B e. X ) -> ( ( A = a /\ B = b ) -> ( ph -> E. x E. y ( <. A , B >. = <. x , y >. /\ [. y / b ]. [. x / a ]. ph ) ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | vex | |- a e. _V |
|
| 2 | vex | |- b e. _V |
|
| 3 | 1 2 | pm3.2i | |- ( a e. _V /\ b e. _V ) |
| 4 | 3 | a1i | |- ( ( A e. X /\ B e. X ) -> ( a e. _V /\ b e. _V ) ) |
| 5 | 4 | anim1ci | |- ( ( ( A e. X /\ B e. X ) /\ ph ) -> ( ph /\ ( a e. _V /\ b e. _V ) ) ) |
| 6 | 5 | adantr | |- ( ( ( ( A e. X /\ B e. X ) /\ ph ) /\ ( A = a /\ B = b ) ) -> ( ph /\ ( a e. _V /\ b e. _V ) ) ) |
| 7 | sbcid | |- ( [. b / b ]. [. a / a ]. ph <-> [. a / a ]. ph ) |
|
| 8 | sbcid | |- ( [. a / a ]. ph <-> ph ) |
|
| 9 | 7 8 | sylbbr | |- ( ph -> [. b / b ]. [. a / a ]. ph ) |
| 10 | 9 | adantl | |- ( ( ( A e. X /\ B e. X ) /\ ph ) -> [. b / b ]. [. a / a ]. ph ) |
| 11 | opeq12 | |- ( ( A = a /\ B = b ) -> <. A , B >. = <. a , b >. ) |
|
| 12 | 10 11 | anim12ci | |- ( ( ( ( A e. X /\ B e. X ) /\ ph ) /\ ( A = a /\ B = b ) ) -> ( <. A , B >. = <. a , b >. /\ [. b / b ]. [. a / a ]. ph ) ) |
| 13 | nfv | |- F/ x ( <. A , B >. = <. a , b >. /\ [. b / b ]. [. a / a ]. ph ) |
|
| 14 | nfv | |- F/ y ( <. A , B >. = <. a , b >. /\ [. b / b ]. [. a / a ]. ph ) |
|
| 15 | opeq12 | |- ( ( x = a /\ y = b ) -> <. x , y >. = <. a , b >. ) |
|
| 16 | 15 | eqeq2d | |- ( ( x = a /\ y = b ) -> ( <. A , B >. = <. x , y >. <-> <. A , B >. = <. a , b >. ) ) |
| 17 | dfsbcq | |- ( y = b -> ( [. y / b ]. [. x / a ]. ph <-> [. b / b ]. [. x / a ]. ph ) ) |
|
| 18 | dfsbcq | |- ( x = a -> ( [. x / a ]. ph <-> [. a / a ]. ph ) ) |
|
| 19 | 18 | sbcbidv | |- ( x = a -> ( [. b / b ]. [. x / a ]. ph <-> [. b / b ]. [. a / a ]. ph ) ) |
| 20 | 17 19 | sylan9bbr | |- ( ( x = a /\ y = b ) -> ( [. y / b ]. [. x / a ]. ph <-> [. b / b ]. [. a / a ]. ph ) ) |
| 21 | 16 20 | anbi12d | |- ( ( x = a /\ y = b ) -> ( ( <. A , B >. = <. x , y >. /\ [. y / b ]. [. x / a ]. ph ) <-> ( <. A , B >. = <. a , b >. /\ [. b / b ]. [. a / a ]. ph ) ) ) |
| 22 | 21 | adantl | |- ( ( ph /\ ( x = a /\ y = b ) ) -> ( ( <. A , B >. = <. x , y >. /\ [. y / b ]. [. x / a ]. ph ) <-> ( <. A , B >. = <. a , b >. /\ [. b / b ]. [. a / a ]. ph ) ) ) |
| 23 | 13 14 22 | spc2ed | |- ( ( ph /\ ( a e. _V /\ b e. _V ) ) -> ( ( <. A , B >. = <. a , b >. /\ [. b / b ]. [. a / a ]. ph ) -> E. x E. y ( <. A , B >. = <. x , y >. /\ [. y / b ]. [. x / a ]. ph ) ) ) |
| 24 | 6 12 23 | sylc | |- ( ( ( ( A e. X /\ B e. X ) /\ ph ) /\ ( A = a /\ B = b ) ) -> E. x E. y ( <. A , B >. = <. x , y >. /\ [. y / b ]. [. x / a ]. ph ) ) |
| 25 | 24 | exp31 | |- ( ( A e. X /\ B e. X ) -> ( ph -> ( ( A = a /\ B = b ) -> E. x E. y ( <. A , B >. = <. x , y >. /\ [. y / b ]. [. x / a ]. ph ) ) ) ) |
| 26 | 25 | com23 | |- ( ( A e. X /\ B e. X ) -> ( ( A = a /\ B = b ) -> ( ph -> E. x E. y ( <. A , B >. = <. x , y >. /\ [. y / b ]. [. x / a ]. ph ) ) ) ) |