Metamath Proof Explorer


Theorem hoadd32i

Description: Commutative/associative law for Hilbert space operator sum that swaps the second and third terms. (Contributed by NM, 27-Jul-2006) (New usage is discouraged.)

Ref Expression
Hypotheses hods.1 𝑅 : ℋ ⟶ ℋ
hods.2 𝑆 : ℋ ⟶ ℋ
hods.3 𝑇 : ℋ ⟶ ℋ
Assertion hoadd32i ( ( 𝑅 +op 𝑆 ) +op 𝑇 ) = ( ( 𝑅 +op 𝑇 ) +op 𝑆 )

Proof

Step Hyp Ref Expression
1 hods.1 𝑅 : ℋ ⟶ ℋ
2 hods.2 𝑆 : ℋ ⟶ ℋ
3 hods.3 𝑇 : ℋ ⟶ ℋ
4 2 3 hoaddcomi ( 𝑆 +op 𝑇 ) = ( 𝑇 +op 𝑆 )
5 4 oveq2i ( 𝑅 +op ( 𝑆 +op 𝑇 ) ) = ( 𝑅 +op ( 𝑇 +op 𝑆 ) )
6 1 2 3 hoaddassi ( ( 𝑅 +op 𝑆 ) +op 𝑇 ) = ( 𝑅 +op ( 𝑆 +op 𝑇 ) )
7 1 3 2 hoaddassi ( ( 𝑅 +op 𝑇 ) +op 𝑆 ) = ( 𝑅 +op ( 𝑇 +op 𝑆 ) )
8 5 6 7 3eqtr4i ( ( 𝑅 +op 𝑆 ) +op 𝑇 ) = ( ( 𝑅 +op 𝑇 ) +op 𝑆 )