Description: Lemma for isosctr . Corresponds to the case where one vertex is at 0. (Contributed by Saveliy Skresanov, 1-Jan-2017)
Ref | Expression | ||
---|---|---|---|
Hypothesis | isosctrlem3.1 | |
|
Assertion | isosctrlem3 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | isosctrlem3.1 | |
|
2 | simp1l | |
|
3 | simp21 | |
|
4 | simp1r | |
|
5 | 2 4 | subcld | |
6 | simp23 | |
|
7 | 2 4 6 | subne0d | |
8 | 1 | angneg | |
9 | 2 3 5 7 8 | syl22anc | |
10 | 2 4 | negsubdi2d | |
11 | 10 | oveq2d | |
12 | 1cnd | |
|
13 | ax-1ne0 | |
|
14 | 13 | a1i | |
15 | 4 2 3 | divcld | |
16 | 12 15 | subcld | |
17 | 6 | necomd | |
18 | 4 2 3 17 | divne1d | |
19 | 18 | necomd | |
20 | 12 15 19 | subne0d | |
21 | 1 12 14 16 20 | angvald | |
22 | 16 | div1d | |
23 | 22 | fveq2d | |
24 | 23 | fveq2d | |
25 | 4 2 3 | absdivd | |
26 | simp3 | |
|
27 | 26 | eqcomd | |
28 | 27 | oveq1d | |
29 | 2 | abscld | |
30 | 29 | recnd | |
31 | 2 3 | absne0d | |
32 | 30 31 | dividd | |
33 | 25 28 32 | 3eqtrd | |
34 | 19 | neneqd | |
35 | isosctrlem2 | |
|
36 | 15 33 34 35 | syl3anc | |
37 | 15 | negcld | |
38 | simp22 | |
|
39 | 4 2 38 3 | divne0d | |
40 | 15 39 | negne0d | |
41 | 1 16 20 37 40 | angvald | |
42 | 36 41 | eqtr4d | |
43 | 21 24 42 | 3eqtrd | |
44 | 2 | mulridd | |
45 | 2 12 15 | subdid | |
46 | 4 2 3 | divcan2d | |
47 | 44 46 | oveq12d | |
48 | 45 47 | eqtrd | |
49 | 44 48 | oveq12d | |
50 | 1 | angcan | |
51 | 12 14 16 20 2 3 50 | syl222anc | |
52 | 49 51 | eqtr3d | |
53 | 2 15 | mulneg2d | |
54 | 46 | negeqd | |
55 | 53 54 | eqtrd | |
56 | 48 55 | oveq12d | |
57 | 1 | angcan | |
58 | 16 20 37 40 2 3 57 | syl222anc | |
59 | 56 58 | eqtr3d | |
60 | 43 52 59 | 3eqtr4d | |
61 | 9 11 60 | 3eqtr3d | |