Description: Lemma for 3cubes . This is Ryley's explicit formula for decomposing a rational A into a sum of three rational cubes. (Contributed by Igor Ieskov, 22-Jan-2024)
Ref | Expression | ||
---|---|---|---|
Hypothesis | 3cubeslem1.a | |
|
Assertion | 3cubeslem4 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 3cubeslem1.a | |
|
2 | 3re | |
|
3 | 2 | a1i | |
4 | 3nn0 | |
|
5 | 4 | a1i | |
6 | 3 5 | reexpcld | |
7 | 6 | mptru | |
8 | 7 | a1i | |
9 | qre | |
|
10 | 4 | a1i | |
11 | 9 10 | reexpcld | |
12 | 1 11 | syl | |
13 | 8 12 | remulcld | |
14 | 1red | |
|
15 | 13 14 | resubcld | |
16 | 15 | recnd | |
17 | 4 | a1i | |
18 | 16 17 | expcld | |
19 | 13 | renegcld | |
20 | 19 | recnd | |
21 | 2 | a1i | |
22 | 21 | recnd | |
23 | 22 | sqcld | |
24 | qcn | |
|
25 | 1 24 | syl | |
26 | 23 25 | mulcld | |
27 | 20 26 | addcld | |
28 | 1cnd | |
|
29 | 27 28 | addcld | |
30 | 29 17 | expcld | |
31 | 8 | recnd | |
32 | 25 | sqcld | |
33 | 31 32 | mulcld | |
34 | 33 26 | addcld | |
35 | 34 22 | addcld | |
36 | 35 17 | expcld | |
37 | 1 | 3cubeslem2 | |
38 | 37 | neqned | |
39 | 3z | |
|
40 | 39 | a1i | |
41 | 35 38 40 | expne0d | |
42 | 18 30 36 41 | divdird | |
43 | 42 | oveq1d | |
44 | 18 30 | addcld | |
45 | 34 17 | expcld | |
46 | 44 45 36 41 | divdird | |
47 | 16 35 38 17 | expdivd | |
48 | 47 | oveq1d | |
49 | 48 | oveq1d | |
50 | 29 35 38 17 | expdivd | |
51 | 50 | oveq2d | |
52 | 51 | oveq1d | |
53 | 34 35 38 17 | expdivd | |
54 | 53 | oveq2d | |
55 | 49 52 54 | 3eqtrd | |
56 | 43 46 55 | 3eqtr4rd | |
57 | 1 | 3cubeslem3 | |
58 | 57 | oveq1d | |
59 | 25 36 41 | divcan4d | |
60 | 56 58 59 | 3eqtr2rd | |