Description: Membership in an intersection implies membership in the second set. (Contributed by Glauco Siliprandi, 2-Jan-2022)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | nel2nelini.1 | ⊢ ¬ 𝐴 ∈ 𝐶 | |
| Assertion | nel2nelini | ⊢ ¬ 𝐴 ∈ ( 𝐵 ∩ 𝐶 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nel2nelini.1 | ⊢ ¬ 𝐴 ∈ 𝐶 | |
| 2 | nel2nelin | ⊢ ( ¬ 𝐴 ∈ 𝐶 → ¬ 𝐴 ∈ ( 𝐵 ∩ 𝐶 ) ) | |
| 3 | 1 2 | ax-mp | ⊢ ¬ 𝐴 ∈ ( 𝐵 ∩ 𝐶 ) |