Description: Equality deduction for well-orderings. (Contributed by Stefan O'Rear, 19-Jan-2015) (Proof shortened by Matthew House, 10-Sep-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | weeq12d.1 | ⊢ ( 𝜑 → 𝑅 = 𝑆 ) | |
| weeq12d.2 | ⊢ ( 𝜑 → 𝐴 = 𝐵 ) | ||
| Assertion | weeq12d | ⊢ ( 𝜑 → ( 𝑅 We 𝐴 ↔ 𝑆 We 𝐵 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | weeq12d.1 | ⊢ ( 𝜑 → 𝑅 = 𝑆 ) | |
| 2 | weeq12d.2 | ⊢ ( 𝜑 → 𝐴 = 𝐵 ) | |
| 3 | weeq1 | ⊢ ( 𝑅 = 𝑆 → ( 𝑅 We 𝐴 ↔ 𝑆 We 𝐴 ) ) | |
| 4 | weeq2 | ⊢ ( 𝐴 = 𝐵 → ( 𝑆 We 𝐴 ↔ 𝑆 We 𝐵 ) ) | |
| 5 | 3 4 | sylan9bb | ⊢ ( ( 𝑅 = 𝑆 ∧ 𝐴 = 𝐵 ) → ( 𝑅 We 𝐴 ↔ 𝑆 We 𝐵 ) ) |
| 6 | 1 2 5 | syl2anc | ⊢ ( 𝜑 → ( 𝑅 We 𝐴 ↔ 𝑆 We 𝐵 ) ) |