Description: Positive Pell solutions are closed under reciprocal. (Contributed by Stefan O'Rear, 18-Sep-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | pell14qrreccl | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pell1234qrreccl | |
|
2 | 1 | adantrr | |
3 | pell1234qrre | |
|
4 | 3 | adantrr | |
5 | simprr | |
|
6 | 4 5 | recgt0d | |
7 | 2 6 | jca | |
8 | 7 | ex | |
9 | elpell14qr2 | |
|
10 | elpell14qr2 | |
|
11 | 8 9 10 | 3imtr4d | |
12 | 11 | imp | |