Metamath Proof Explorer


Theorem dmadjrn

Description: The adjoint of an operator belongs to the adjoint function's domain. (Contributed by NM, 15-Feb-2006) (New usage is discouraged.)

Ref Expression
Assertion dmadjrn ( 𝑇 ∈ dom adjℎ → ( adjℎ ‘ 𝑇 ) ∈ dom adjℎ )

Proof

Step Hyp Ref Expression
1 adj1o ⊢ adjℎ : dom adjℎ –1-1-onto→ dom adjℎ
2 f1of ⊢ ( adjℎ : dom adjℎ –1-1-onto→ dom adjℎ → adjℎ : dom adjℎ ⟶ dom adjℎ )
3 1 2 ax-mp ⊢ adjℎ : dom adjℎ ⟶ dom adjℎ
4 3 ffvelcdmi ⊢ ( 𝑇 ∈ dom adjℎ → ( adjℎ ‘ 𝑇 ) ∈ dom adjℎ )