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Description: The union of a quotient set. More restrictive antecedent; kept for backward compatibility; for new work, prefer uniqs . (Contributed by NM, 9-Dec-2008) (Proof shortened by AV, 25-Nov-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | uniqsw | ⊢ ( 𝑅 ∈ 𝑉 → ∪ ( 𝐴 / 𝑅 ) = ( 𝑅 “ 𝐴 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | resexg | ⊢ ( 𝑅 ∈ 𝑉 → ( 𝑅 ↾ 𝐴 ) ∈ V ) | |
| 2 | uniqs | ⊢ ( ( 𝑅 ↾ 𝐴 ) ∈ V → ∪ ( 𝐴 / 𝑅 ) = ( 𝑅 “ 𝐴 ) ) | |
| 3 | 1 2 | syl | ⊢ ( 𝑅 ∈ 𝑉 → ∪ ( 𝐴 / 𝑅 ) = ( 𝑅 “ 𝐴 ) ) |