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Metamath Proof Explorer


Theorem hoival

Description: The value of the Hilbert space identity operator. (Contributed by NM, 8-Aug-2006) (New usage is discouraged.)

Ref Expression
Assertion hoival ( 𝐴 ∈ ℋ → ( Iop𝐴 ) = 𝐴 )

Proof

Step Hyp Ref Expression
1 df-iop Iop = ( proj ‘ ℋ )
2 1 fveq1i ( Iop𝐴 ) = ( ( proj ‘ ℋ ) ‘ 𝐴 )
3 pjch1 ( 𝐴 ∈ ℋ → ( ( proj ‘ ℋ ) ‘ 𝐴 ) = 𝐴 )
4 2 3 eqtrid ( 𝐴 ∈ ℋ → ( Iop𝐴 ) = 𝐴 )