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 ) |