Description: Equality inference for ordered pairs. (Contributed by NM, 16-Dec-2006) (Proof shortened by Eric Schmidt, 4-Apr-2007)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | opeq1i.1 | ⊢ 𝐴 = 𝐵 | |
| opeq12i.2 | ⊢ 𝐶 = 𝐷 | ||
| Assertion | opeq12i | ⊢ 〈 𝐴 , 𝐶 〉 = 〈 𝐵 , 𝐷 〉 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | opeq1i.1 | ⊢ 𝐴 = 𝐵 | |
| 2 | opeq12i.2 | ⊢ 𝐶 = 𝐷 | |
| 3 | opeq12 | ⊢ ( ( 𝐴 = 𝐵 ∧ 𝐶 = 𝐷 ) → 〈 𝐴 , 𝐶 〉 = 〈 𝐵 , 𝐷 〉 ) | |
| 4 | 1 2 3 | mp2an | ⊢ 〈 𝐴 , 𝐶 〉 = 〈 𝐵 , 𝐷 〉 |