Description: Equality theorem for the well-ordering predicate. (Contributed by NM, 3-Apr-1994)
Ref | Expression | ||
---|---|---|---|
Assertion | weeq2 | ⊢ ( 𝐴 = 𝐵 → ( 𝑅 We 𝐴 ↔ 𝑅 We 𝐵 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | freq2 | ⊢ ( 𝐴 = 𝐵 → ( 𝑅 Fr 𝐴 ↔ 𝑅 Fr 𝐵 ) ) | |
2 | soeq2 | ⊢ ( 𝐴 = 𝐵 → ( 𝑅 Or 𝐴 ↔ 𝑅 Or 𝐵 ) ) | |
3 | 1 2 | anbi12d | ⊢ ( 𝐴 = 𝐵 → ( ( 𝑅 Fr 𝐴 ∧ 𝑅 Or 𝐴 ) ↔ ( 𝑅 Fr 𝐵 ∧ 𝑅 Or 𝐵 ) ) ) |
4 | df-we | ⊢ ( 𝑅 We 𝐴 ↔ ( 𝑅 Fr 𝐴 ∧ 𝑅 Or 𝐴 ) ) | |
5 | df-we | ⊢ ( 𝑅 We 𝐵 ↔ ( 𝑅 Fr 𝐵 ∧ 𝑅 Or 𝐵 ) ) | |
6 | 3 4 5 | 3bitr4g | ⊢ ( 𝐴 = 𝐵 → ( 𝑅 We 𝐴 ↔ 𝑅 We 𝐵 ) ) |