Step |
Hyp |
Ref |
Expression |
1 |
|
btwncomand.1 |
|- ( ph -> N e. NN ) |
2 |
|
btwncomand.2 |
|- ( ph -> A e. ( EE ` N ) ) |
3 |
|
btwncomand.3 |
|- ( ph -> B e. ( EE ` N ) ) |
4 |
|
btwncomand.4 |
|- ( ph -> C e. ( EE ` N ) ) |
5 |
|
btwncomand.5 |
|- ( ( ph /\ ps ) -> A Btwn <. B , C >. ) |
6 |
|
btwncom |
|- ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) -> ( A Btwn <. B , C >. <-> A Btwn <. C , B >. ) ) |
7 |
1 2 3 4 6
|
syl13anc |
|- ( ph -> ( A Btwn <. B , C >. <-> A Btwn <. C , B >. ) ) |
8 |
7
|
adantr |
|- ( ( ph /\ ps ) -> ( A Btwn <. B , C >. <-> A Btwn <. C , B >. ) ) |
9 |
5 8
|
mpbid |
|- ( ( ph /\ ps ) -> A Btwn <. C , B >. ) |