This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Equality theorem for substitution of a class A for an ordered pair <. x , y >. in B (analogue of csbeq1a ). (Contributed by NM, 19-Aug-2006) (Revised by Mario Carneiro, 31-Aug-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | csbopeq1a | ⊢ ( 𝐴 = 〈 𝑥 , 𝑦 〉 → ⦋ ( 1st ‘ 𝐴 ) / 𝑥 ⦌ ⦋ ( 2nd ‘ 𝐴 ) / 𝑦 ⦌ 𝐵 = 𝐵 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | vex | ⊢ 𝑥 ∈ V | |
| 2 | vex | ⊢ 𝑦 ∈ V | |
| 3 | 1 2 | op2ndd | ⊢ ( 𝐴 = 〈 𝑥 , 𝑦 〉 → ( 2nd ‘ 𝐴 ) = 𝑦 ) |
| 4 | 3 | eqcomd | ⊢ ( 𝐴 = 〈 𝑥 , 𝑦 〉 → 𝑦 = ( 2nd ‘ 𝐴 ) ) |
| 5 | csbeq1a | ⊢ ( 𝑦 = ( 2nd ‘ 𝐴 ) → 𝐵 = ⦋ ( 2nd ‘ 𝐴 ) / 𝑦 ⦌ 𝐵 ) | |
| 6 | 4 5 | syl | ⊢ ( 𝐴 = 〈 𝑥 , 𝑦 〉 → 𝐵 = ⦋ ( 2nd ‘ 𝐴 ) / 𝑦 ⦌ 𝐵 ) |
| 7 | 1 2 | op1std | ⊢ ( 𝐴 = 〈 𝑥 , 𝑦 〉 → ( 1st ‘ 𝐴 ) = 𝑥 ) |
| 8 | 7 | eqcomd | ⊢ ( 𝐴 = 〈 𝑥 , 𝑦 〉 → 𝑥 = ( 1st ‘ 𝐴 ) ) |
| 9 | csbeq1a | ⊢ ( 𝑥 = ( 1st ‘ 𝐴 ) → ⦋ ( 2nd ‘ 𝐴 ) / 𝑦 ⦌ 𝐵 = ⦋ ( 1st ‘ 𝐴 ) / 𝑥 ⦌ ⦋ ( 2nd ‘ 𝐴 ) / 𝑦 ⦌ 𝐵 ) | |
| 10 | 8 9 | syl | ⊢ ( 𝐴 = 〈 𝑥 , 𝑦 〉 → ⦋ ( 2nd ‘ 𝐴 ) / 𝑦 ⦌ 𝐵 = ⦋ ( 1st ‘ 𝐴 ) / 𝑥 ⦌ ⦋ ( 2nd ‘ 𝐴 ) / 𝑦 ⦌ 𝐵 ) |
| 11 | 6 10 | eqtr2d | ⊢ ( 𝐴 = 〈 𝑥 , 𝑦 〉 → ⦋ ( 1st ‘ 𝐴 ) / 𝑥 ⦌ ⦋ ( 2nd ‘ 𝐴 ) / 𝑦 ⦌ 𝐵 = 𝐵 ) |