Step |
Hyp |
Ref |
Expression |
1 |
|
mulgt0b2d.a |
|- ( ph -> A e. RR ) |
2 |
|
mulgt0b2d.b |
|- ( ph -> B e. RR ) |
3 |
|
mulgt0b2d.1 |
|- ( ph -> 0 < A ) |
4 |
1
|
adantr |
|- ( ( ph /\ 0 < B ) -> A e. RR ) |
5 |
2
|
adantr |
|- ( ( ph /\ 0 < B ) -> B e. RR ) |
6 |
3
|
adantr |
|- ( ( ph /\ 0 < B ) -> 0 < A ) |
7 |
|
simpr |
|- ( ( ph /\ 0 < B ) -> 0 < B ) |
8 |
4 5 6 7
|
mulgt0d |
|- ( ( ph /\ 0 < B ) -> 0 < ( A x. B ) ) |
9 |
8
|
ex |
|- ( ph -> ( 0 < B -> 0 < ( A x. B ) ) ) |
10 |
1
|
adantr |
|- ( ( ph /\ ( ( A x. B ) x. ( 0 -R 1 ) ) < 0 ) -> A e. RR ) |
11 |
|
1re |
|- 1 e. RR |
12 |
|
rernegcl |
|- ( 1 e. RR -> ( 0 -R 1 ) e. RR ) |
13 |
11 12
|
mp1i |
|- ( ph -> ( 0 -R 1 ) e. RR ) |
14 |
2 13
|
remulcld |
|- ( ph -> ( B x. ( 0 -R 1 ) ) e. RR ) |
15 |
14
|
adantr |
|- ( ( ph /\ ( ( A x. B ) x. ( 0 -R 1 ) ) < 0 ) -> ( B x. ( 0 -R 1 ) ) e. RR ) |
16 |
3
|
adantr |
|- ( ( ph /\ ( ( A x. B ) x. ( 0 -R 1 ) ) < 0 ) -> 0 < A ) |
17 |
1
|
recnd |
|- ( ph -> A e. CC ) |
18 |
2
|
recnd |
|- ( ph -> B e. CC ) |
19 |
13
|
recnd |
|- ( ph -> ( 0 -R 1 ) e. CC ) |
20 |
17 18 19
|
mulassd |
|- ( ph -> ( ( A x. B ) x. ( 0 -R 1 ) ) = ( A x. ( B x. ( 0 -R 1 ) ) ) ) |
21 |
20
|
breq1d |
|- ( ph -> ( ( ( A x. B ) x. ( 0 -R 1 ) ) < 0 <-> ( A x. ( B x. ( 0 -R 1 ) ) ) < 0 ) ) |
22 |
21
|
biimpa |
|- ( ( ph /\ ( ( A x. B ) x. ( 0 -R 1 ) ) < 0 ) -> ( A x. ( B x. ( 0 -R 1 ) ) ) < 0 ) |
23 |
10 15 16 22
|
mulgt0con2d |
|- ( ( ph /\ ( ( A x. B ) x. ( 0 -R 1 ) ) < 0 ) -> ( B x. ( 0 -R 1 ) ) < 0 ) |
24 |
23
|
ex |
|- ( ph -> ( ( ( A x. B ) x. ( 0 -R 1 ) ) < 0 -> ( B x. ( 0 -R 1 ) ) < 0 ) ) |
25 |
1 2
|
remulcld |
|- ( ph -> ( A x. B ) e. RR ) |
26 |
|
relt0neg2 |
|- ( ( A x. B ) e. RR -> ( 0 < ( A x. B ) <-> ( 0 -R ( A x. B ) ) < 0 ) ) |
27 |
25 26
|
syl |
|- ( ph -> ( 0 < ( A x. B ) <-> ( 0 -R ( A x. B ) ) < 0 ) ) |
28 |
|
0red |
|- ( ph -> 0 e. RR ) |
29 |
|
1red |
|- ( ph -> 1 e. RR ) |
30 |
|
resubdi |
|- ( ( ( A x. B ) e. RR /\ 0 e. RR /\ 1 e. RR ) -> ( ( A x. B ) x. ( 0 -R 1 ) ) = ( ( ( A x. B ) x. 0 ) -R ( ( A x. B ) x. 1 ) ) ) |
31 |
25 28 29 30
|
syl3anc |
|- ( ph -> ( ( A x. B ) x. ( 0 -R 1 ) ) = ( ( ( A x. B ) x. 0 ) -R ( ( A x. B ) x. 1 ) ) ) |
32 |
|
remul01 |
|- ( ( A x. B ) e. RR -> ( ( A x. B ) x. 0 ) = 0 ) |
33 |
|
ax-1rid |
|- ( ( A x. B ) e. RR -> ( ( A x. B ) x. 1 ) = ( A x. B ) ) |
34 |
32 33
|
oveq12d |
|- ( ( A x. B ) e. RR -> ( ( ( A x. B ) x. 0 ) -R ( ( A x. B ) x. 1 ) ) = ( 0 -R ( A x. B ) ) ) |
35 |
25 34
|
syl |
|- ( ph -> ( ( ( A x. B ) x. 0 ) -R ( ( A x. B ) x. 1 ) ) = ( 0 -R ( A x. B ) ) ) |
36 |
31 35
|
eqtrd |
|- ( ph -> ( ( A x. B ) x. ( 0 -R 1 ) ) = ( 0 -R ( A x. B ) ) ) |
37 |
36
|
breq1d |
|- ( ph -> ( ( ( A x. B ) x. ( 0 -R 1 ) ) < 0 <-> ( 0 -R ( A x. B ) ) < 0 ) ) |
38 |
27 37
|
bitr4d |
|- ( ph -> ( 0 < ( A x. B ) <-> ( ( A x. B ) x. ( 0 -R 1 ) ) < 0 ) ) |
39 |
|
relt0neg2 |
|- ( B e. RR -> ( 0 < B <-> ( 0 -R B ) < 0 ) ) |
40 |
2 39
|
syl |
|- ( ph -> ( 0 < B <-> ( 0 -R B ) < 0 ) ) |
41 |
|
resubdi |
|- ( ( B e. RR /\ 0 e. RR /\ 1 e. RR ) -> ( B x. ( 0 -R 1 ) ) = ( ( B x. 0 ) -R ( B x. 1 ) ) ) |
42 |
2 28 29 41
|
syl3anc |
|- ( ph -> ( B x. ( 0 -R 1 ) ) = ( ( B x. 0 ) -R ( B x. 1 ) ) ) |
43 |
|
remul01 |
|- ( B e. RR -> ( B x. 0 ) = 0 ) |
44 |
|
ax-1rid |
|- ( B e. RR -> ( B x. 1 ) = B ) |
45 |
43 44
|
oveq12d |
|- ( B e. RR -> ( ( B x. 0 ) -R ( B x. 1 ) ) = ( 0 -R B ) ) |
46 |
2 45
|
syl |
|- ( ph -> ( ( B x. 0 ) -R ( B x. 1 ) ) = ( 0 -R B ) ) |
47 |
42 46
|
eqtrd |
|- ( ph -> ( B x. ( 0 -R 1 ) ) = ( 0 -R B ) ) |
48 |
47
|
breq1d |
|- ( ph -> ( ( B x. ( 0 -R 1 ) ) < 0 <-> ( 0 -R B ) < 0 ) ) |
49 |
40 48
|
bitr4d |
|- ( ph -> ( 0 < B <-> ( B x. ( 0 -R 1 ) ) < 0 ) ) |
50 |
24 38 49
|
3imtr4d |
|- ( ph -> ( 0 < ( A x. B ) -> 0 < B ) ) |
51 |
9 50
|
impbid |
|- ( ph -> ( 0 < B <-> 0 < ( A x. B ) ) ) |