Theorem cnlnadj

Description: Every continuous linear operator has an adjoint. Theorem 3.10 of Beran p. 104. (Contributed by NM, 18-Feb-2006) (New usage is discouraged.)

	Ref	Expression
Assertion	cnlnadj	⊢ ( 𝑇 ∈ ( LinOp ∩ ContOp ) → ∃ 𝑡 ∈ ( LinOp ∩ ContOp ) ∀ 𝑥 ∈ ℋ ∀ 𝑦 ∈ ℋ ( ( 𝑇 ‘ 𝑥 ) ·ih 𝑦 ) = ( 𝑥 ·ih ( 𝑡 ‘ 𝑦 ) ) )

Proof

Step	Hyp	Ref	Expression
1		cnlnadjeu	⊢ ( 𝑇 ∈ ( LinOp ∩ ContOp ) → ∃! 𝑡 ∈ ( LinOp ∩ ContOp ) ∀ 𝑥 ∈ ℋ ∀ 𝑦 ∈ ℋ ( ( 𝑇 ‘ 𝑥 ) ·ih 𝑦 ) = ( 𝑥 ·ih ( 𝑡 ‘ 𝑦 ) ) )
2		reurex	⊢ ( ∃! 𝑡 ∈ ( LinOp ∩ ContOp ) ∀ 𝑥 ∈ ℋ ∀ 𝑦 ∈ ℋ ( ( 𝑇 ‘ 𝑥 ) ·ih 𝑦 ) = ( 𝑥 ·ih ( 𝑡 ‘ 𝑦 ) ) → ∃ 𝑡 ∈ ( LinOp ∩ ContOp ) ∀ 𝑥 ∈ ℋ ∀ 𝑦 ∈ ℋ ( ( 𝑇 ‘ 𝑥 ) ·ih 𝑦 ) = ( 𝑥 ·ih ( 𝑡 ‘ 𝑦 ) ) )
3	1 2	syl	⊢ ( 𝑇 ∈ ( LinOp ∩ ContOp ) → ∃ 𝑡 ∈ ( LinOp ∩ ContOp ) ∀ 𝑥 ∈ ℋ ∀ 𝑦 ∈ ℋ ( ( 𝑇 ‘ 𝑥 ) ·ih 𝑦 ) = ( 𝑥 ·ih ( 𝑡 ‘ 𝑦 ) ) )