| Step |
Hyp |
Ref |
Expression |
| 1 |
|
0nonelaleb.1 |
|- ( ph -> A e. RR ) |
| 2 |
|
0nonelaleb.2 |
|- ( ph -> B e. RR ) |
| 3 |
|
0nonelaleb.3 |
|- ( ph -> 0 < A ) |
| 4 |
|
0nonelaleb.4 |
|- ( ph -> A <_ B ) |
| 5 |
|
0nonelalab.5 |
|- ( ph -> C e. ( A (,) B ) ) |
| 6 |
|
0red |
|- ( ph -> 0 e. RR ) |
| 7 |
|
elioore |
|- ( C e. ( A (,) B ) -> C e. RR ) |
| 8 |
5 7
|
syl |
|- ( ph -> C e. RR ) |
| 9 |
1
|
rexrd |
|- ( ph -> A e. RR* ) |
| 10 |
2
|
rexrd |
|- ( ph -> B e. RR* ) |
| 11 |
|
elioo2 |
|- ( ( A e. RR* /\ B e. RR* ) -> ( C e. ( A (,) B ) <-> ( C e. RR /\ A < C /\ C < B ) ) ) |
| 12 |
9 10 11
|
syl2anc |
|- ( ph -> ( C e. ( A (,) B ) <-> ( C e. RR /\ A < C /\ C < B ) ) ) |
| 13 |
5 12
|
mpbid |
|- ( ph -> ( C e. RR /\ A < C /\ C < B ) ) |
| 14 |
13
|
simp2d |
|- ( ph -> A < C ) |
| 15 |
6 1 8 3 14
|
lttrd |
|- ( ph -> 0 < C ) |
| 16 |
6 15
|
ltned |
|- ( ph -> 0 =/= C ) |