Description: Positive Pell solutions are closed under integer powers. (Contributed by Stefan O'Rear, 18-Sep-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | pell14qrexpcl | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elznn0 | |
|
2 | simplll | |
|
3 | simpllr | |
|
4 | simpr | |
|
5 | pell14qrexpclnn0 | |
|
6 | 2 3 4 5 | syl3anc | |
7 | pell14qrre | |
|
8 | 7 | recnd | |
9 | 8 | ad2antrr | |
10 | simplr | |
|
11 | 10 | recnd | |
12 | simpr | |
|
13 | expneg2 | |
|
14 | 9 11 12 13 | syl3anc | |
15 | simplll | |
|
16 | simpllr | |
|
17 | pell14qrexpclnn0 | |
|
18 | 15 16 12 17 | syl3anc | |
19 | pell14qrreccl | |
|
20 | 15 18 19 | syl2anc | |
21 | 14 20 | eqeltrd | |
22 | 6 21 | jaodan | |
23 | 22 | expl | |
24 | 1 23 | biimtrid | |
25 | 24 | 3impia | |