Theorem pell1234qrre

Description: General Pell solutions are (coded as) real numbers. (Contributed by Stefan O'Rear, 17-Sep-2014)

	Ref	Expression
Assertion	pell1234qrre	⊢ ( ( 𝐷 ∈ ( ℕ ∖ ◻NN ) ∧ 𝐴 ∈ ( Pell1234QR ‘ 𝐷 ) ) → 𝐴 ∈ ℝ )

Proof

Step	Hyp	Ref	Expression
1		elpell1234qr	⊢ ( 𝐷 ∈ ( ℕ ∖ ◻NN ) → ( 𝐴 ∈ ( Pell1234QR ‘ 𝐷 ) ↔ ( 𝐴 ∈ ℝ ∧ ∃ 𝑎 ∈ ℤ ∃ 𝑏 ∈ ℤ ( 𝐴 = ( 𝑎 + ( ( √ ‘ 𝐷 ) · 𝑏 ) ) ∧ ( ( 𝑎 ↑ 2 ) − ( 𝐷 · ( 𝑏 ↑ 2 ) ) ) = 1 ) ) ) )
2	1	simprbda	⊢ ( ( 𝐷 ∈ ( ℕ ∖ ◻NN ) ∧ 𝐴 ∈ ( Pell1234QR ‘ 𝐷 ) ) → 𝐴 ∈ ℝ )