| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elpell1234qr |  |-  ( D e. ( NN \ []NN ) -> ( A e. ( Pell1234QR ` D ) <-> ( A e. RR /\ E. a e. ZZ E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) ) ) | 
						
							| 2 |  | simp-4r |  |-  ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ a e. NN0 ) /\ E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> A e. RR ) | 
						
							| 3 |  | oveq1 |  |-  ( c = a -> ( c + ( ( sqrt ` D ) x. b ) ) = ( a + ( ( sqrt ` D ) x. b ) ) ) | 
						
							| 4 | 3 | eqeq2d |  |-  ( c = a -> ( A = ( c + ( ( sqrt ` D ) x. b ) ) <-> A = ( a + ( ( sqrt ` D ) x. b ) ) ) ) | 
						
							| 5 |  | oveq1 |  |-  ( c = a -> ( c ^ 2 ) = ( a ^ 2 ) ) | 
						
							| 6 | 5 | oveq1d |  |-  ( c = a -> ( ( c ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) ) | 
						
							| 7 | 6 | eqeq1d |  |-  ( c = a -> ( ( ( c ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 <-> ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) | 
						
							| 8 | 4 7 | anbi12d |  |-  ( c = a -> ( ( A = ( c + ( ( sqrt ` D ) x. b ) ) /\ ( ( c ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) <-> ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) ) | 
						
							| 9 | 8 | rexbidv |  |-  ( c = a -> ( E. b e. ZZ ( A = ( c + ( ( sqrt ` D ) x. b ) ) /\ ( ( c ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) <-> E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) ) | 
						
							| 10 | 9 | rspcev |  |-  ( ( a e. NN0 /\ E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> E. c e. NN0 E. b e. ZZ ( A = ( c + ( ( sqrt ` D ) x. b ) ) /\ ( ( c ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) | 
						
							| 11 | 10 | adantll |  |-  ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ a e. NN0 ) /\ E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> E. c e. NN0 E. b e. ZZ ( A = ( c + ( ( sqrt ` D ) x. b ) ) /\ ( ( c ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) | 
						
							| 12 |  | elpell14qr |  |-  ( D e. ( NN \ []NN ) -> ( A e. ( Pell14QR ` D ) <-> ( A e. RR /\ E. c e. NN0 E. b e. ZZ ( A = ( c + ( ( sqrt ` D ) x. b ) ) /\ ( ( c ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) ) ) | 
						
							| 13 | 12 | ad4antr |  |-  ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ a e. NN0 ) /\ E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( A e. ( Pell14QR ` D ) <-> ( A e. RR /\ E. c e. NN0 E. b e. ZZ ( A = ( c + ( ( sqrt ` D ) x. b ) ) /\ ( ( c ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) ) ) | 
						
							| 14 | 2 11 13 | mpbir2and |  |-  ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ a e. NN0 ) /\ E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> A e. ( Pell14QR ` D ) ) | 
						
							| 15 | 14 | orcd |  |-  ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ a e. NN0 ) /\ E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( A e. ( Pell14QR ` D ) \/ -u A e. ( Pell14QR ` D ) ) ) | 
						
							| 16 | 15 | exp31 |  |-  ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) -> ( a e. NN0 -> ( E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) -> ( A e. ( Pell14QR ` D ) \/ -u A e. ( Pell14QR ` D ) ) ) ) ) | 
						
							| 17 |  | simp-5r |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> A e. RR ) | 
						
							| 18 | 17 | renegcld |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> -u A e. RR ) | 
						
							| 19 |  | simpllr |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> -u a e. NN0 ) | 
						
							| 20 |  | znegcl |  |-  ( b e. ZZ -> -u b e. ZZ ) | 
						
							| 21 | 20 | ad2antlr |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> -u b e. ZZ ) | 
						
							| 22 |  | simprl |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> A = ( a + ( ( sqrt ` D ) x. b ) ) ) | 
						
							| 23 | 22 | negeqd |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> -u A = -u ( a + ( ( sqrt ` D ) x. b ) ) ) | 
						
							| 24 |  | zcn |  |-  ( a e. ZZ -> a e. CC ) | 
						
							| 25 | 24 | ad4antlr |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> a e. CC ) | 
						
							| 26 |  | eldifi |  |-  ( D e. ( NN \ []NN ) -> D e. NN ) | 
						
							| 27 | 26 | nncnd |  |-  ( D e. ( NN \ []NN ) -> D e. CC ) | 
						
							| 28 | 27 | ad5antr |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> D e. CC ) | 
						
							| 29 | 28 | sqrtcld |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( sqrt ` D ) e. CC ) | 
						
							| 30 |  | zcn |  |-  ( b e. ZZ -> b e. CC ) | 
						
							| 31 | 30 | ad2antlr |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> b e. CC ) | 
						
							| 32 | 29 31 | mulcld |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( ( sqrt ` D ) x. b ) e. CC ) | 
						
							| 33 | 25 32 | negdid |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> -u ( a + ( ( sqrt ` D ) x. b ) ) = ( -u a + -u ( ( sqrt ` D ) x. b ) ) ) | 
						
							| 34 |  | mulneg2 |  |-  ( ( ( sqrt ` D ) e. CC /\ b e. CC ) -> ( ( sqrt ` D ) x. -u b ) = -u ( ( sqrt ` D ) x. b ) ) | 
						
							| 35 | 34 | eqcomd |  |-  ( ( ( sqrt ` D ) e. CC /\ b e. CC ) -> -u ( ( sqrt ` D ) x. b ) = ( ( sqrt ` D ) x. -u b ) ) | 
						
							| 36 | 29 31 35 | syl2anc |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> -u ( ( sqrt ` D ) x. b ) = ( ( sqrt ` D ) x. -u b ) ) | 
						
							| 37 | 36 | oveq2d |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( -u a + -u ( ( sqrt ` D ) x. b ) ) = ( -u a + ( ( sqrt ` D ) x. -u b ) ) ) | 
						
							| 38 | 23 33 37 | 3eqtrd |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> -u A = ( -u a + ( ( sqrt ` D ) x. -u b ) ) ) | 
						
							| 39 |  | sqneg |  |-  ( a e. CC -> ( -u a ^ 2 ) = ( a ^ 2 ) ) | 
						
							| 40 | 25 39 | syl |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( -u a ^ 2 ) = ( a ^ 2 ) ) | 
						
							| 41 |  | sqneg |  |-  ( b e. CC -> ( -u b ^ 2 ) = ( b ^ 2 ) ) | 
						
							| 42 | 31 41 | syl |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( -u b ^ 2 ) = ( b ^ 2 ) ) | 
						
							| 43 | 42 | oveq2d |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( D x. ( -u b ^ 2 ) ) = ( D x. ( b ^ 2 ) ) ) | 
						
							| 44 | 40 43 | oveq12d |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( ( -u a ^ 2 ) - ( D x. ( -u b ^ 2 ) ) ) = ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) ) | 
						
							| 45 |  | simprr |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) | 
						
							| 46 | 44 45 | eqtrd |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( ( -u a ^ 2 ) - ( D x. ( -u b ^ 2 ) ) ) = 1 ) | 
						
							| 47 |  | oveq1 |  |-  ( c = -u a -> ( c + ( ( sqrt ` D ) x. d ) ) = ( -u a + ( ( sqrt ` D ) x. d ) ) ) | 
						
							| 48 | 47 | eqeq2d |  |-  ( c = -u a -> ( -u A = ( c + ( ( sqrt ` D ) x. d ) ) <-> -u A = ( -u a + ( ( sqrt ` D ) x. d ) ) ) ) | 
						
							| 49 |  | oveq1 |  |-  ( c = -u a -> ( c ^ 2 ) = ( -u a ^ 2 ) ) | 
						
							| 50 | 49 | oveq1d |  |-  ( c = -u a -> ( ( c ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = ( ( -u a ^ 2 ) - ( D x. ( d ^ 2 ) ) ) ) | 
						
							| 51 | 50 | eqeq1d |  |-  ( c = -u a -> ( ( ( c ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = 1 <-> ( ( -u a ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = 1 ) ) | 
						
							| 52 | 48 51 | anbi12d |  |-  ( c = -u a -> ( ( -u A = ( c + ( ( sqrt ` D ) x. d ) ) /\ ( ( c ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = 1 ) <-> ( -u A = ( -u a + ( ( sqrt ` D ) x. d ) ) /\ ( ( -u a ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = 1 ) ) ) | 
						
							| 53 |  | oveq2 |  |-  ( d = -u b -> ( ( sqrt ` D ) x. d ) = ( ( sqrt ` D ) x. -u b ) ) | 
						
							| 54 | 53 | oveq2d |  |-  ( d = -u b -> ( -u a + ( ( sqrt ` D ) x. d ) ) = ( -u a + ( ( sqrt ` D ) x. -u b ) ) ) | 
						
							| 55 | 54 | eqeq2d |  |-  ( d = -u b -> ( -u A = ( -u a + ( ( sqrt ` D ) x. d ) ) <-> -u A = ( -u a + ( ( sqrt ` D ) x. -u b ) ) ) ) | 
						
							| 56 |  | oveq1 |  |-  ( d = -u b -> ( d ^ 2 ) = ( -u b ^ 2 ) ) | 
						
							| 57 | 56 | oveq2d |  |-  ( d = -u b -> ( D x. ( d ^ 2 ) ) = ( D x. ( -u b ^ 2 ) ) ) | 
						
							| 58 | 57 | oveq2d |  |-  ( d = -u b -> ( ( -u a ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = ( ( -u a ^ 2 ) - ( D x. ( -u b ^ 2 ) ) ) ) | 
						
							| 59 | 58 | eqeq1d |  |-  ( d = -u b -> ( ( ( -u a ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = 1 <-> ( ( -u a ^ 2 ) - ( D x. ( -u b ^ 2 ) ) ) = 1 ) ) | 
						
							| 60 | 55 59 | anbi12d |  |-  ( d = -u b -> ( ( -u A = ( -u a + ( ( sqrt ` D ) x. d ) ) /\ ( ( -u a ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = 1 ) <-> ( -u A = ( -u a + ( ( sqrt ` D ) x. -u b ) ) /\ ( ( -u a ^ 2 ) - ( D x. ( -u b ^ 2 ) ) ) = 1 ) ) ) | 
						
							| 61 | 52 60 | rspc2ev |  |-  ( ( -u a e. NN0 /\ -u b e. ZZ /\ ( -u A = ( -u a + ( ( sqrt ` D ) x. -u b ) ) /\ ( ( -u a ^ 2 ) - ( D x. ( -u b ^ 2 ) ) ) = 1 ) ) -> E. c e. NN0 E. d e. ZZ ( -u A = ( c + ( ( sqrt ` D ) x. d ) ) /\ ( ( c ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = 1 ) ) | 
						
							| 62 | 19 21 38 46 61 | syl112anc |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> E. c e. NN0 E. d e. ZZ ( -u A = ( c + ( ( sqrt ` D ) x. d ) ) /\ ( ( c ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = 1 ) ) | 
						
							| 63 |  | elpell14qr |  |-  ( D e. ( NN \ []NN ) -> ( -u A e. ( Pell14QR ` D ) <-> ( -u A e. RR /\ E. c e. NN0 E. d e. ZZ ( -u A = ( c + ( ( sqrt ` D ) x. d ) ) /\ ( ( c ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = 1 ) ) ) ) | 
						
							| 64 | 63 | ad5antr |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( -u A e. ( Pell14QR ` D ) <-> ( -u A e. RR /\ E. c e. NN0 E. d e. ZZ ( -u A = ( c + ( ( sqrt ` D ) x. d ) ) /\ ( ( c ^ 2 ) - ( D x. ( d ^ 2 ) ) ) = 1 ) ) ) ) | 
						
							| 65 | 18 62 64 | mpbir2and |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> -u A e. ( Pell14QR ` D ) ) | 
						
							| 66 | 65 | olcd |  |-  ( ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) /\ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( A e. ( Pell14QR ` D ) \/ -u A e. ( Pell14QR ` D ) ) ) | 
						
							| 67 | 66 | ex |  |-  ( ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) /\ b e. ZZ ) -> ( ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) -> ( A e. ( Pell14QR ` D ) \/ -u A e. ( Pell14QR ` D ) ) ) ) | 
						
							| 68 | 67 | rexlimdva |  |-  ( ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) /\ -u a e. NN0 ) -> ( E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) -> ( A e. ( Pell14QR ` D ) \/ -u A e. ( Pell14QR ` D ) ) ) ) | 
						
							| 69 | 68 | ex |  |-  ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) -> ( -u a e. NN0 -> ( E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) -> ( A e. ( Pell14QR ` D ) \/ -u A e. ( Pell14QR ` D ) ) ) ) ) | 
						
							| 70 |  | elznn0 |  |-  ( a e. ZZ <-> ( a e. RR /\ ( a e. NN0 \/ -u a e. NN0 ) ) ) | 
						
							| 71 | 70 | simprbi |  |-  ( a e. ZZ -> ( a e. NN0 \/ -u a e. NN0 ) ) | 
						
							| 72 | 71 | adantl |  |-  ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) -> ( a e. NN0 \/ -u a e. NN0 ) ) | 
						
							| 73 | 16 69 72 | mpjaod |  |-  ( ( ( D e. ( NN \ []NN ) /\ A e. RR ) /\ a e. ZZ ) -> ( E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) -> ( A e. ( Pell14QR ` D ) \/ -u A e. ( Pell14QR ` D ) ) ) ) | 
						
							| 74 | 73 | rexlimdva |  |-  ( ( D e. ( NN \ []NN ) /\ A e. RR ) -> ( E. a e. ZZ E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) -> ( A e. ( Pell14QR ` D ) \/ -u A e. ( Pell14QR ` D ) ) ) ) | 
						
							| 75 | 74 | expimpd |  |-  ( D e. ( NN \ []NN ) -> ( ( A e. RR /\ E. a e. ZZ E. b e. ZZ ( A = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) -> ( A e. ( Pell14QR ` D ) \/ -u A e. ( Pell14QR ` D ) ) ) ) | 
						
							| 76 | 1 75 | sylbid |  |-  ( D e. ( NN \ []NN ) -> ( A e. ( Pell1234QR ` D ) -> ( A e. ( Pell14QR ` D ) \/ -u A e. ( Pell14QR ` D ) ) ) ) | 
						
							| 77 | 76 | imp |  |-  ( ( D e. ( NN \ []NN ) /\ A e. ( Pell1234QR ` D ) ) -> ( A e. ( Pell14QR ` D ) \/ -u A e. ( Pell14QR ` D ) ) ) |