Description: Define Cartesian products of alternative ordered pairs. (Contributed by Scott Fenton, 23-Mar-2012)
Ref | Expression | ||
---|---|---|---|
Assertion | df-altxp | ⊢ ( 𝐴 ×× 𝐵 ) = { 𝑧 ∣ ∃ 𝑥 ∈ 𝐴 ∃ 𝑦 ∈ 𝐵 𝑧 = ⟪ 𝑥 , 𝑦 ⟫ } |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cA | ⊢ 𝐴 | |
1 | cB | ⊢ 𝐵 | |
2 | 0 1 | caltxp | ⊢ ( 𝐴 ×× 𝐵 ) |
3 | vz | ⊢ 𝑧 | |
4 | vx | ⊢ 𝑥 | |
5 | vy | ⊢ 𝑦 | |
6 | 3 | cv | ⊢ 𝑧 |
7 | 4 | cv | ⊢ 𝑥 |
8 | 5 | cv | ⊢ 𝑦 |
9 | 7 8 | caltop | ⊢ ⟪ 𝑥 , 𝑦 ⟫ |
10 | 6 9 | wceq | ⊢ 𝑧 = ⟪ 𝑥 , 𝑦 ⟫ |
11 | 10 5 1 | wrex | ⊢ ∃ 𝑦 ∈ 𝐵 𝑧 = ⟪ 𝑥 , 𝑦 ⟫ |
12 | 11 4 0 | wrex | ⊢ ∃ 𝑥 ∈ 𝐴 ∃ 𝑦 ∈ 𝐵 𝑧 = ⟪ 𝑥 , 𝑦 ⟫ |
13 | 12 3 | cab | ⊢ { 𝑧 ∣ ∃ 𝑥 ∈ 𝐴 ∃ 𝑦 ∈ 𝐵 𝑧 = ⟪ 𝑥 , 𝑦 ⟫ } |
14 | 2 13 | wceq | ⊢ ( 𝐴 ×× 𝐵 ) = { 𝑧 ∣ ∃ 𝑥 ∈ 𝐴 ∃ 𝑦 ∈ 𝐵 𝑧 = ⟪ 𝑥 , 𝑦 ⟫ } |