Description: Subclass theorem for disjoint elementhood, inference version. (Contributed by Peter Mazsa, 28-Sep-2021)
Ref | Expression | ||
---|---|---|---|
Hypothesis | eldisjssi.1 | ⊢ 𝐴 ⊆ 𝐵 | |
Assertion | eldisjssi | ⊢ ( ElDisj 𝐵 → ElDisj 𝐴 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eldisjssi.1 | ⊢ 𝐴 ⊆ 𝐵 | |
2 | eldisjss | ⊢ ( 𝐴 ⊆ 𝐵 → ( ElDisj 𝐵 → ElDisj 𝐴 ) ) | |
3 | 1 2 | ax-mp | ⊢ ( ElDisj 𝐵 → ElDisj 𝐴 ) |