Description: Pull back a well ordering by a one-to-one function. (Contributed by Eric Schmidt, 4-Aug-2026)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | f1owe.1 | ⊢ 𝑅 = { 〈 𝑥 , 𝑦 〉 ∣ ( 𝐹 ‘ 𝑥 ) 𝑆 ( 𝐹 ‘ 𝑦 ) } | |
| Assertion | f1we | ⊢ ( 𝐹 : 𝐴 –1-1→ 𝐵 → ( 𝑆 We 𝐵 → 𝑅 We 𝐴 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | f1owe.1 | ⊢ 𝑅 = { 〈 𝑥 , 𝑦 〉 ∣ ( 𝐹 ‘ 𝑥 ) 𝑆 ( 𝐹 ‘ 𝑦 ) } | |
| 2 | f1f | ⊢ ( 𝐹 : 𝐴 –1-1→ 𝐵 → 𝐹 : 𝐴 ⟶ 𝐵 ) | |
| 3 | frn | ⊢ ( 𝐹 : 𝐴 ⟶ 𝐵 → ran 𝐹 ⊆ 𝐵 ) | |
| 4 | wess | ⊢ ( ran 𝐹 ⊆ 𝐵 → ( 𝑆 We 𝐵 → 𝑆 We ran 𝐹 ) ) | |
| 5 | 2 3 4 | 3syl | ⊢ ( 𝐹 : 𝐴 –1-1→ 𝐵 → ( 𝑆 We 𝐵 → 𝑆 We ran 𝐹 ) ) |
| 6 | f1f1orn | ⊢ ( 𝐹 : 𝐴 –1-1→ 𝐵 → 𝐹 : 𝐴 –1-1-onto→ ran 𝐹 ) | |
| 7 | 1 | f1owe | ⊢ ( 𝐹 : 𝐴 –1-1-onto→ ran 𝐹 → ( 𝑅 We 𝐴 ↔ 𝑆 We ran 𝐹 ) ) |
| 8 | 6 7 | syl | ⊢ ( 𝐹 : 𝐴 –1-1→ 𝐵 → ( 𝑅 We 𝐴 ↔ 𝑆 We ran 𝐹 ) ) |
| 9 | 5 8 | sylibrd | ⊢ ( 𝐹 : 𝐴 –1-1→ 𝐵 → ( 𝑆 We 𝐵 → 𝑅 We 𝐴 ) ) |