Description: Lemma for petincnvepres2 . (Contributed by Peter Mazsa, 31-Dec-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | eqvrelqseqdisj4 | ⊢ ( ( EqvRel 𝑅 ∧ ( 𝐵 / 𝑅 ) = 𝐴 ) → Disj ( 𝑆 ∩ ( ◡ E ↾ 𝐴 ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eqvrelqseqdisj3 | ⊢ ( ( EqvRel 𝑅 ∧ ( 𝐵 / 𝑅 ) = 𝐴 ) → Disj ( ◡ E ↾ 𝐴 ) ) | |
| 2 | disjimin | ⊢ ( Disj ( ◡ E ↾ 𝐴 ) → Disj ( 𝑆 ∩ ( ◡ E ↾ 𝐴 ) ) ) | |
| 3 | 1 2 | syl | ⊢ ( ( EqvRel 𝑅 ∧ ( 𝐵 / 𝑅 ) = 𝐴 ) → Disj ( 𝑆 ∩ ( ◡ E ↾ 𝐴 ) ) ) |