Description: Equivalent wff's yield equal restricted class abstractions. (Contributed by Thierry Arnoux, 4-Feb-2017)
Ref | Expression | ||
---|---|---|---|
Hypothesis | rabbidva2.1 | ⊢ ( 𝜑 → ( ( 𝑥 ∈ 𝐴 ∧ 𝜓 ) ↔ ( 𝑥 ∈ 𝐵 ∧ 𝜒 ) ) ) | |
Assertion | rabbidva2 | ⊢ ( 𝜑 → { 𝑥 ∈ 𝐴 ∣ 𝜓 } = { 𝑥 ∈ 𝐵 ∣ 𝜒 } ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | rabbidva2.1 | ⊢ ( 𝜑 → ( ( 𝑥 ∈ 𝐴 ∧ 𝜓 ) ↔ ( 𝑥 ∈ 𝐵 ∧ 𝜒 ) ) ) | |
2 | 1 | abbidv | ⊢ ( 𝜑 → { 𝑥 ∣ ( 𝑥 ∈ 𝐴 ∧ 𝜓 ) } = { 𝑥 ∣ ( 𝑥 ∈ 𝐵 ∧ 𝜒 ) } ) |
3 | df-rab | ⊢ { 𝑥 ∈ 𝐴 ∣ 𝜓 } = { 𝑥 ∣ ( 𝑥 ∈ 𝐴 ∧ 𝜓 ) } | |
4 | df-rab | ⊢ { 𝑥 ∈ 𝐵 ∣ 𝜒 } = { 𝑥 ∣ ( 𝑥 ∈ 𝐵 ∧ 𝜒 ) } | |
5 | 2 3 4 | 3eqtr4g | ⊢ ( 𝜑 → { 𝑥 ∈ 𝐴 ∣ 𝜓 } = { 𝑥 ∈ 𝐵 ∣ 𝜒 } ) |