Description: Swap with a membership relation in a restricted class abstraction. (Contributed by NM, 4-Jul-2005)
Ref | Expression | ||
---|---|---|---|
Assertion | rabswap | ⊢ { 𝑥 ∈ 𝐴 ∣ 𝑥 ∈ 𝐵 } = { 𝑥 ∈ 𝐵 ∣ 𝑥 ∈ 𝐴 } |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ancom | ⊢ ( ( 𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵 ) ↔ ( 𝑥 ∈ 𝐵 ∧ 𝑥 ∈ 𝐴 ) ) | |
2 | 1 | rabbia2 | ⊢ { 𝑥 ∈ 𝐴 ∣ 𝑥 ∈ 𝐵 } = { 𝑥 ∈ 𝐵 ∣ 𝑥 ∈ 𝐴 } |