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 ) |