Description: Membership implication from subclass relationship. (Contributed by NM, 5-Aug-1993)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | sseli.1 | ⊢ 𝐴 ⊆ 𝐵 | |
| Assertion | sseli | ⊢ ( 𝐶 ∈ 𝐴 → 𝐶 ∈ 𝐵 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sseli.1 | ⊢ 𝐴 ⊆ 𝐵 | |
| 2 | ssel | ⊢ ( 𝐴 ⊆ 𝐵 → ( 𝐶 ∈ 𝐴 → 𝐶 ∈ 𝐵 ) ) | |
| 3 | 1 2 | ax-mp | ⊢ ( 𝐶 ∈ 𝐴 → 𝐶 ∈ 𝐵 ) |