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 ) |