Description: Version of rabeqbidva with two disjoint variable conditions removed and the third replaced by a nonfreeness hypothesis. (Contributed by BJ, 27-Apr-2019)
Ref | Expression | ||
---|---|---|---|
Hypotheses | bj-rabeqbida.nf | ⊢ Ⅎ 𝑥 𝜑 | |
bj-rabeqbida.1 | ⊢ ( 𝜑 → 𝐴 = 𝐵 ) | ||
bj-rabeqbida.2 | ⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → ( 𝜓 ↔ 𝜒 ) ) | ||
Assertion | bj-rabeqbida | ⊢ ( 𝜑 → { 𝑥 ∈ 𝐴 ∣ 𝜓 } = { 𝑥 ∈ 𝐵 ∣ 𝜒 } ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | bj-rabeqbida.nf | ⊢ Ⅎ 𝑥 𝜑 | |
2 | bj-rabeqbida.1 | ⊢ ( 𝜑 → 𝐴 = 𝐵 ) | |
3 | bj-rabeqbida.2 | ⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → ( 𝜓 ↔ 𝜒 ) ) | |
4 | 1 3 | rabbida | ⊢ ( 𝜑 → { 𝑥 ∈ 𝐴 ∣ 𝜓 } = { 𝑥 ∈ 𝐴 ∣ 𝜒 } ) |
5 | 1 2 | bj-rabeqd | ⊢ ( 𝜑 → { 𝑥 ∈ 𝐴 ∣ 𝜒 } = { 𝑥 ∈ 𝐵 ∣ 𝜒 } ) |
6 | 4 5 | eqtrd | ⊢ ( 𝜑 → { 𝑥 ∈ 𝐴 ∣ 𝜓 } = { 𝑥 ∈ 𝐵 ∣ 𝜒 } ) |