Step |
Hyp |
Ref |
Expression |
1 |
|
btwnexch3and.1 |
|- ( ph -> N e. NN ) |
2 |
|
btwnexch3and.2 |
|- ( ph -> A e. ( EE ` N ) ) |
3 |
|
btwnexch3and.3 |
|- ( ph -> B e. ( EE ` N ) ) |
4 |
|
btwnexch3and.4 |
|- ( ph -> C e. ( EE ` N ) ) |
5 |
|
btwnexch3and.5 |
|- ( ph -> D e. ( EE ` N ) ) |
6 |
|
btwnexch3and.6 |
|- ( ( ph /\ ps ) -> B Btwn <. A , C >. ) |
7 |
|
btwnexch3and.7 |
|- ( ( ph /\ ps ) -> C Btwn <. A , D >. ) |
8 |
|
btwnexch3 |
|- ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) ) /\ ( C e. ( EE ` N ) /\ D e. ( EE ` N ) ) ) -> ( ( B Btwn <. A , C >. /\ C Btwn <. A , D >. ) -> C Btwn <. B , D >. ) ) |
9 |
1 2 3 4 5 8
|
syl122anc |
|- ( ph -> ( ( B Btwn <. A , C >. /\ C Btwn <. A , D >. ) -> C Btwn <. B , D >. ) ) |
10 |
9
|
adantr |
|- ( ( ph /\ ps ) -> ( ( B Btwn <. A , C >. /\ C Btwn <. A , D >. ) -> C Btwn <. B , D >. ) ) |
11 |
6 7 10
|
mp2and |
|- ( ( ph /\ ps ) -> C Btwn <. B , D >. ) |