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 ) ) ) |