Metamath Proof Explorer


Theorem hmopadj2

Description: An operator is Hermitian iff it is self-adjoint. Definition of Hermitian in Halmos p. 41. (Contributed by NM, 9-Apr-2006) (New usage is discouraged.)

Ref Expression
Assertion hmopadj2 ( 𝑇 ∈ dom adj → ( 𝑇 ∈ HrmOp ↔ ( adj𝑇 ) = 𝑇 ) )

Proof

Step Hyp Ref Expression
1 hmopadj ( 𝑇 ∈ HrmOp → ( adj𝑇 ) = 𝑇 )
2 dmadjop ( 𝑇 ∈ dom adj𝑇 : ℋ ⟶ ℋ )
3 2 adantr ( ( 𝑇 ∈ dom adj ∧ ( adj𝑇 ) = 𝑇 ) → 𝑇 : ℋ ⟶ ℋ )
4 adj1 ( ( 𝑇 ∈ dom adj𝑥 ∈ ℋ ∧ 𝑦 ∈ ℋ ) → ( 𝑥 ·ih ( 𝑇𝑦 ) ) = ( ( ( adj𝑇 ) ‘ 𝑥 ) ·ih 𝑦 ) )
5 4 3expb ( ( 𝑇 ∈ dom adj ∧ ( 𝑥 ∈ ℋ ∧ 𝑦 ∈ ℋ ) ) → ( 𝑥 ·ih ( 𝑇𝑦 ) ) = ( ( ( adj𝑇 ) ‘ 𝑥 ) ·ih 𝑦 ) )
6 5 adantlr ( ( ( 𝑇 ∈ dom adj ∧ ( adj𝑇 ) = 𝑇 ) ∧ ( 𝑥 ∈ ℋ ∧ 𝑦 ∈ ℋ ) ) → ( 𝑥 ·ih ( 𝑇𝑦 ) ) = ( ( ( adj𝑇 ) ‘ 𝑥 ) ·ih 𝑦 ) )
7 fveq1 ( ( adj𝑇 ) = 𝑇 → ( ( adj𝑇 ) ‘ 𝑥 ) = ( 𝑇𝑥 ) )
8 7 oveq1d ( ( adj𝑇 ) = 𝑇 → ( ( ( adj𝑇 ) ‘ 𝑥 ) ·ih 𝑦 ) = ( ( 𝑇𝑥 ) ·ih 𝑦 ) )
9 8 ad2antlr ( ( ( 𝑇 ∈ dom adj ∧ ( adj𝑇 ) = 𝑇 ) ∧ ( 𝑥 ∈ ℋ ∧ 𝑦 ∈ ℋ ) ) → ( ( ( adj𝑇 ) ‘ 𝑥 ) ·ih 𝑦 ) = ( ( 𝑇𝑥 ) ·ih 𝑦 ) )
10 6 9 eqtrd ( ( ( 𝑇 ∈ dom adj ∧ ( adj𝑇 ) = 𝑇 ) ∧ ( 𝑥 ∈ ℋ ∧ 𝑦 ∈ ℋ ) ) → ( 𝑥 ·ih ( 𝑇𝑦 ) ) = ( ( 𝑇𝑥 ) ·ih 𝑦 ) )
11 10 ralrimivva ( ( 𝑇 ∈ dom adj ∧ ( adj𝑇 ) = 𝑇 ) → ∀ 𝑥 ∈ ℋ ∀ 𝑦 ∈ ℋ ( 𝑥 ·ih ( 𝑇𝑦 ) ) = ( ( 𝑇𝑥 ) ·ih 𝑦 ) )
12 elhmop ( 𝑇 ∈ HrmOp ↔ ( 𝑇 : ℋ ⟶ ℋ ∧ ∀ 𝑥 ∈ ℋ ∀ 𝑦 ∈ ℋ ( 𝑥 ·ih ( 𝑇𝑦 ) ) = ( ( 𝑇𝑥 ) ·ih 𝑦 ) ) )
13 3 11 12 sylanbrc ( ( 𝑇 ∈ dom adj ∧ ( adj𝑇 ) = 𝑇 ) → 𝑇 ∈ HrmOp )
14 13 ex ( 𝑇 ∈ dom adj → ( ( adj𝑇 ) = 𝑇𝑇 ∈ HrmOp ) )
15 1 14 impbid2 ( 𝑇 ∈ dom adj → ( 𝑇 ∈ HrmOp ↔ ( adj𝑇 ) = 𝑇 ) )