Metamath Proof Explorer


Theorem pellfundre

Description: The fundamental solution of a Pell equation exists as a real number. (Contributed by Stefan O'Rear, 18-Sep-2014)

Ref Expression
Assertion pellfundre D PellFund D

Proof

Step Hyp Ref Expression
1 pellfundval D PellFund D = sup a Pell14QR D | 1 < a <
2 ssrab2 a Pell14QR D | 1 < a Pell14QR D
3 pell14qrre D a Pell14QR D a
4 3 ex D a Pell14QR D a
5 4 ssrdv D Pell14QR D
6 2 5 sstrid D a Pell14QR D | 1 < a
7 pell1qrss14 D Pell1QR D Pell14QR D
8 pellqrex D a Pell1QR D 1 < a
9 ssrexv Pell1QR D Pell14QR D a Pell1QR D 1 < a a Pell14QR D 1 < a
10 7 8 9 sylc D a Pell14QR D 1 < a
11 rabn0 a Pell14QR D | 1 < a a Pell14QR D 1 < a
12 10 11 sylibr D a Pell14QR D | 1 < a
13 1re 1
14 breq2 a = c 1 < a 1 < c
15 14 elrab c a Pell14QR D | 1 < a c Pell14QR D 1 < c
16 pell14qrre D c Pell14QR D c
17 ltle 1 c 1 < c 1 c
18 13 16 17 sylancr D c Pell14QR D 1 < c 1 c
19 18 expimpd D c Pell14QR D 1 < c 1 c
20 15 19 syl5bi D c a Pell14QR D | 1 < a 1 c
21 20 ralrimiv D c a Pell14QR D | 1 < a 1 c
22 breq1 b = 1 b c 1 c
23 22 ralbidv b = 1 c a Pell14QR D | 1 < a b c c a Pell14QR D | 1 < a 1 c
24 23 rspcev 1 c a Pell14QR D | 1 < a 1 c b c a Pell14QR D | 1 < a b c
25 13 21 24 sylancr D b c a Pell14QR D | 1 < a b c
26 infrecl a Pell14QR D | 1 < a a Pell14QR D | 1 < a b c a Pell14QR D | 1 < a b c sup a Pell14QR D | 1 < a <
27 6 12 25 26 syl3anc D sup a Pell14QR D | 1 < a <
28 1 27 eqeltrd D PellFund D