Description: Prove if ( A e. CH , A , ~H ) e. CH . (Contributed by David A. Wheeler, 8-Dec-2018) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | ifchhv | ⊢ if ( 𝐴 ∈ Cℋ , 𝐴 , ℋ ) ∈ Cℋ |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | helch | ⊢ ℋ ∈ Cℋ | |
2 | 1 | elimel | ⊢ if ( 𝐴 ∈ Cℋ , 𝐴 , ℋ ) ∈ Cℋ |