Description: Two balls are disjoint if the center-to-center distance is more than the sum of the radii. (Contributed by Mario Carneiro, 30-Dec-2013)
Ref | Expression | ||
---|---|---|---|
Assertion | bldisj | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpr3 | |
|
2 | simpr1 | |
|
3 | simpr2 | |
|
4 | 2 3 | xaddcld | |
5 | xmetcl | |
|
6 | 5 | adantr | |
7 | 4 6 | xrlenltd | |
8 | 1 7 | mpbid | |
9 | elin | |
|
10 | simpl1 | |
|
11 | simpl2 | |
|
12 | elbl | |
|
13 | 10 11 2 12 | syl3anc | |
14 | simpl3 | |
|
15 | elbl | |
|
16 | 10 14 3 15 | syl3anc | |
17 | 13 16 | anbi12d | |
18 | anandi | |
|
19 | 17 18 | bitr4di | |
20 | 10 | adantr | |
21 | 11 | adantr | |
22 | simpr | |
|
23 | xmetcl | |
|
24 | 20 21 22 23 | syl3anc | |
25 | 14 | adantr | |
26 | xmetcl | |
|
27 | 20 25 22 26 | syl3anc | |
28 | 2 | adantr | |
29 | 3 | adantr | |
30 | xlt2add | |
|
31 | 24 27 28 29 30 | syl22anc | |
32 | xmettri3 | |
|
33 | 20 21 25 22 32 | syl13anc | |
34 | 6 | adantr | |
35 | 24 27 | xaddcld | |
36 | 4 | adantr | |
37 | xrlelttr | |
|
38 | 34 35 36 37 | syl3anc | |
39 | 33 38 | mpand | |
40 | 31 39 | syld | |
41 | 40 | expimpd | |
42 | 19 41 | sylbid | |
43 | 9 42 | biimtrid | |
44 | 8 43 | mtod | |
45 | 44 | eq0rdv | |