Description: Membership in a restricted intersection. (Contributed by Stefan O'Rear, 3-Apr-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | elrint2 | ⊢ ( 𝑋 ∈ 𝐴 → ( 𝑋 ∈ ( 𝐴 ∩ ∩ 𝐵 ) ↔ ∀ 𝑦 ∈ 𝐵 𝑋 ∈ 𝑦 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elrint | ⊢ ( 𝑋 ∈ ( 𝐴 ∩ ∩ 𝐵 ) ↔ ( 𝑋 ∈ 𝐴 ∧ ∀ 𝑦 ∈ 𝐵 𝑋 ∈ 𝑦 ) ) | |
| 2 | 1 | baib | ⊢ ( 𝑋 ∈ 𝐴 → ( 𝑋 ∈ ( 𝐴 ∩ ∩ 𝐵 ) ↔ ∀ 𝑦 ∈ 𝐵 𝑋 ∈ 𝑦 ) ) |