# Metamath Proof Explorer

## Theorem rmxyelxp

Description: Lemma for frmx and frmy . (Contributed by Stefan O'Rear, 22-Sep-2014)

Ref Expression
Assertion rmxyelxp
`|- ( ( A e. ( ZZ>= ` 2 ) /\ N e. ZZ ) -> ( `' ( b e. ( NN0 X. ZZ ) |-> ( ( 1st ` b ) + ( ( sqrt ` ( ( A ^ 2 ) - 1 ) ) x. ( 2nd ` b ) ) ) ) ` ( ( A + ( sqrt ` ( ( A ^ 2 ) - 1 ) ) ) ^ N ) ) e. ( NN0 X. ZZ ) )`

### Proof

Step Hyp Ref Expression
1 rmxypairf1o
` |-  ( A e. ( ZZ>= ` 2 ) -> ( b e. ( NN0 X. ZZ ) |-> ( ( 1st ` b ) + ( ( sqrt ` ( ( A ^ 2 ) - 1 ) ) x. ( 2nd ` b ) ) ) ) : ( NN0 X. ZZ ) -1-1-onto-> { a | E. c e. NN0 E. d e. ZZ a = ( c + ( ( sqrt ` ( ( A ^ 2 ) - 1 ) ) x. d ) ) } )`
` |-  ( ( A e. ( ZZ>= ` 2 ) /\ N e. ZZ ) -> ( b e. ( NN0 X. ZZ ) |-> ( ( 1st ` b ) + ( ( sqrt ` ( ( A ^ 2 ) - 1 ) ) x. ( 2nd ` b ) ) ) ) : ( NN0 X. ZZ ) -1-1-onto-> { a | E. c e. NN0 E. d e. ZZ a = ( c + ( ( sqrt ` ( ( A ^ 2 ) - 1 ) ) x. d ) ) } )`
` |-  ( ( A e. ( ZZ>= ` 2 ) /\ N e. ZZ ) -> ( ( A + ( sqrt ` ( ( A ^ 2 ) - 1 ) ) ) ^ N ) e. { a | E. c e. NN0 E. d e. ZZ a = ( c + ( ( sqrt ` ( ( A ^ 2 ) - 1 ) ) x. d ) ) } )`
` |-  ( ( ( b e. ( NN0 X. ZZ ) |-> ( ( 1st ` b ) + ( ( sqrt ` ( ( A ^ 2 ) - 1 ) ) x. ( 2nd ` b ) ) ) ) : ( NN0 X. ZZ ) -1-1-onto-> { a | E. c e. NN0 E. d e. ZZ a = ( c + ( ( sqrt ` ( ( A ^ 2 ) - 1 ) ) x. d ) ) } /\ ( ( A + ( sqrt ` ( ( A ^ 2 ) - 1 ) ) ) ^ N ) e. { a | E. c e. NN0 E. d e. ZZ a = ( c + ( ( sqrt ` ( ( A ^ 2 ) - 1 ) ) x. d ) ) } ) -> ( `' ( b e. ( NN0 X. ZZ ) |-> ( ( 1st ` b ) + ( ( sqrt ` ( ( A ^ 2 ) - 1 ) ) x. ( 2nd ` b ) ) ) ) ` ( ( A + ( sqrt ` ( ( A ^ 2 ) - 1 ) ) ) ^ N ) ) e. ( NN0 X. ZZ ) )`
` |-  ( ( A e. ( ZZ>= ` 2 ) /\ N e. ZZ ) -> ( `' ( b e. ( NN0 X. ZZ ) |-> ( ( 1st ` b ) + ( ( sqrt ` ( ( A ^ 2 ) - 1 ) ) x. ( 2nd ` b ) ) ) ) ` ( ( A + ( sqrt ` ( ( A ^ 2 ) - 1 ) ) ) ^ N ) ) e. ( NN0 X. ZZ ) )`