| Step |
Hyp |
Ref |
Expression |
| 1 |
|
mdsymlem1.1 |
|- A e. CH |
| 2 |
|
mdsymlem1.2 |
|- B e. CH |
| 3 |
|
mdsymlem1.3 |
|- C = ( A vH p ) |
| 4 |
1 2 3
|
mdsymlem4 |
|- ( p e. HAtoms -> ( ( B MH* A /\ ( ( A =/= 0H /\ B =/= 0H ) /\ p C_ ( A vH B ) ) ) -> E. q e. HAtoms E. r e. HAtoms ( p C_ ( q vH r ) /\ ( q C_ A /\ r C_ B ) ) ) ) |
| 5 |
4
|
exp4d |
|- ( p e. HAtoms -> ( B MH* A -> ( ( A =/= 0H /\ B =/= 0H ) -> ( p C_ ( A vH B ) -> E. q e. HAtoms E. r e. HAtoms ( p C_ ( q vH r ) /\ ( q C_ A /\ r C_ B ) ) ) ) ) ) |
| 6 |
5
|
com13 |
|- ( ( A =/= 0H /\ B =/= 0H ) -> ( B MH* A -> ( p e. HAtoms -> ( p C_ ( A vH B ) -> E. q e. HAtoms E. r e. HAtoms ( p C_ ( q vH r ) /\ ( q C_ A /\ r C_ B ) ) ) ) ) ) |
| 7 |
6
|
ralrimdv |
|- ( ( A =/= 0H /\ B =/= 0H ) -> ( B MH* A -> A. p e. HAtoms ( p C_ ( A vH B ) -> E. q e. HAtoms E. r e. HAtoms ( p C_ ( q vH r ) /\ ( q C_ A /\ r C_ B ) ) ) ) ) |
| 8 |
1 2 3
|
mdsymlem6 |
|- ( A. p e. HAtoms ( p C_ ( A vH B ) -> E. q e. HAtoms E. r e. HAtoms ( p C_ ( q vH r ) /\ ( q C_ A /\ r C_ B ) ) ) -> B MH* A ) |
| 9 |
7 8
|
impbid1 |
|- ( ( A =/= 0H /\ B =/= 0H ) -> ( B MH* A <-> A. p e. HAtoms ( p C_ ( A vH B ) -> E. q e. HAtoms E. r e. HAtoms ( p C_ ( q vH r ) /\ ( q C_ A /\ r C_ B ) ) ) ) ) |