| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 1red |  |-  ( D e. ( NN \ []NN ) -> 1 e. RR ) | 
						
							| 2 |  | 1nn0 |  |-  1 e. NN0 | 
						
							| 3 | 2 | a1i |  |-  ( D e. ( NN \ []NN ) -> 1 e. NN0 ) | 
						
							| 4 |  | 0nn0 |  |-  0 e. NN0 | 
						
							| 5 | 4 | a1i |  |-  ( D e. ( NN \ []NN ) -> 0 e. NN0 ) | 
						
							| 6 |  | eldifi |  |-  ( D e. ( NN \ []NN ) -> D e. NN ) | 
						
							| 7 | 6 | nncnd |  |-  ( D e. ( NN \ []NN ) -> D e. CC ) | 
						
							| 8 | 7 | sqrtcld |  |-  ( D e. ( NN \ []NN ) -> ( sqrt ` D ) e. CC ) | 
						
							| 9 | 8 | mul01d |  |-  ( D e. ( NN \ []NN ) -> ( ( sqrt ` D ) x. 0 ) = 0 ) | 
						
							| 10 | 9 | oveq2d |  |-  ( D e. ( NN \ []NN ) -> ( 1 + ( ( sqrt ` D ) x. 0 ) ) = ( 1 + 0 ) ) | 
						
							| 11 |  | 1p0e1 |  |-  ( 1 + 0 ) = 1 | 
						
							| 12 | 10 11 | eqtr2di |  |-  ( D e. ( NN \ []NN ) -> 1 = ( 1 + ( ( sqrt ` D ) x. 0 ) ) ) | 
						
							| 13 |  | sq1 |  |-  ( 1 ^ 2 ) = 1 | 
						
							| 14 | 13 | a1i |  |-  ( D e. ( NN \ []NN ) -> ( 1 ^ 2 ) = 1 ) | 
						
							| 15 |  | sq0 |  |-  ( 0 ^ 2 ) = 0 | 
						
							| 16 | 15 | oveq2i |  |-  ( D x. ( 0 ^ 2 ) ) = ( D x. 0 ) | 
						
							| 17 | 7 | mul01d |  |-  ( D e. ( NN \ []NN ) -> ( D x. 0 ) = 0 ) | 
						
							| 18 | 16 17 | eqtrid |  |-  ( D e. ( NN \ []NN ) -> ( D x. ( 0 ^ 2 ) ) = 0 ) | 
						
							| 19 | 14 18 | oveq12d |  |-  ( D e. ( NN \ []NN ) -> ( ( 1 ^ 2 ) - ( D x. ( 0 ^ 2 ) ) ) = ( 1 - 0 ) ) | 
						
							| 20 |  | 1m0e1 |  |-  ( 1 - 0 ) = 1 | 
						
							| 21 | 19 20 | eqtrdi |  |-  ( D e. ( NN \ []NN ) -> ( ( 1 ^ 2 ) - ( D x. ( 0 ^ 2 ) ) ) = 1 ) | 
						
							| 22 |  | oveq1 |  |-  ( a = 1 -> ( a + ( ( sqrt ` D ) x. b ) ) = ( 1 + ( ( sqrt ` D ) x. b ) ) ) | 
						
							| 23 | 22 | eqeq2d |  |-  ( a = 1 -> ( 1 = ( a + ( ( sqrt ` D ) x. b ) ) <-> 1 = ( 1 + ( ( sqrt ` D ) x. b ) ) ) ) | 
						
							| 24 |  | oveq1 |  |-  ( a = 1 -> ( a ^ 2 ) = ( 1 ^ 2 ) ) | 
						
							| 25 | 24 | oveq1d |  |-  ( a = 1 -> ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = ( ( 1 ^ 2 ) - ( D x. ( b ^ 2 ) ) ) ) | 
						
							| 26 | 25 | eqeq1d |  |-  ( a = 1 -> ( ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 <-> ( ( 1 ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) | 
						
							| 27 | 23 26 | anbi12d |  |-  ( a = 1 -> ( ( 1 = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) <-> ( 1 = ( 1 + ( ( sqrt ` D ) x. b ) ) /\ ( ( 1 ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) ) | 
						
							| 28 |  | oveq2 |  |-  ( b = 0 -> ( ( sqrt ` D ) x. b ) = ( ( sqrt ` D ) x. 0 ) ) | 
						
							| 29 | 28 | oveq2d |  |-  ( b = 0 -> ( 1 + ( ( sqrt ` D ) x. b ) ) = ( 1 + ( ( sqrt ` D ) x. 0 ) ) ) | 
						
							| 30 | 29 | eqeq2d |  |-  ( b = 0 -> ( 1 = ( 1 + ( ( sqrt ` D ) x. b ) ) <-> 1 = ( 1 + ( ( sqrt ` D ) x. 0 ) ) ) ) | 
						
							| 31 |  | oveq1 |  |-  ( b = 0 -> ( b ^ 2 ) = ( 0 ^ 2 ) ) | 
						
							| 32 | 31 | oveq2d |  |-  ( b = 0 -> ( D x. ( b ^ 2 ) ) = ( D x. ( 0 ^ 2 ) ) ) | 
						
							| 33 | 32 | oveq2d |  |-  ( b = 0 -> ( ( 1 ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = ( ( 1 ^ 2 ) - ( D x. ( 0 ^ 2 ) ) ) ) | 
						
							| 34 | 33 | eqeq1d |  |-  ( b = 0 -> ( ( ( 1 ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 <-> ( ( 1 ^ 2 ) - ( D x. ( 0 ^ 2 ) ) ) = 1 ) ) | 
						
							| 35 | 30 34 | anbi12d |  |-  ( b = 0 -> ( ( 1 = ( 1 + ( ( sqrt ` D ) x. b ) ) /\ ( ( 1 ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) <-> ( 1 = ( 1 + ( ( sqrt ` D ) x. 0 ) ) /\ ( ( 1 ^ 2 ) - ( D x. ( 0 ^ 2 ) ) ) = 1 ) ) ) | 
						
							| 36 | 27 35 | rspc2ev |  |-  ( ( 1 e. NN0 /\ 0 e. NN0 /\ ( 1 = ( 1 + ( ( sqrt ` D ) x. 0 ) ) /\ ( ( 1 ^ 2 ) - ( D x. ( 0 ^ 2 ) ) ) = 1 ) ) -> E. a e. NN0 E. b e. NN0 ( 1 = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) | 
						
							| 37 | 3 5 12 21 36 | syl112anc |  |-  ( D e. ( NN \ []NN ) -> E. a e. NN0 E. b e. NN0 ( 1 = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) | 
						
							| 38 |  | elpell1qr |  |-  ( D e. ( NN \ []NN ) -> ( 1 e. ( Pell1QR ` D ) <-> ( 1 e. RR /\ E. a e. NN0 E. b e. NN0 ( 1 = ( a + ( ( sqrt ` D ) x. b ) ) /\ ( ( a ^ 2 ) - ( D x. ( b ^ 2 ) ) ) = 1 ) ) ) ) | 
						
							| 39 | 1 37 38 | mpbir2and |  |-  ( D e. ( NN \ []NN ) -> 1 e. ( Pell1QR ` D ) ) |