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 〉 |