Metamath Proof Explorer


Definition df-altxp

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 ⟫ }

Detailed syntax breakdown

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 ⟫ }