Metamath Proof Explorer


Definition df-cnv2

Description: Define a function that returns the second converse of a set. The second converse of a set takes all ordered triples in the set and rotates them so the last argument becomes the first argument. Based on Definition 14.1(1) of TakeutiZaring p. 143. (Contributed by BTernaryTau, 2-Sep-2026)

Ref Expression
Assertion df-cnv2 Cnv2 = ( 𝑤 ∈ V ↦ { ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∣ ⟨ ⟨ 𝑧 , 𝑥 ⟩ , 𝑦 ⟩ ∈ 𝑤 } )

Detailed syntax breakdown

Step Hyp Ref Expression
0 ccnv2 ⊢ Cnv2
1 vw ⊢ 𝑤
2 cvv ⊢ V
3 vx ⊢ 𝑥
4 vy ⊢ 𝑦
5 vz ⊢ 𝑧
6 5 cv ⊢ 𝑧
7 3 cv ⊢ 𝑥
8 6 7 cop ⊢ ⟨ 𝑧 , 𝑥 ⟩
9 4 cv ⊢ 𝑦
10 8 9 cop ⊢ ⟨ ⟨ 𝑧 , 𝑥 ⟩ , 𝑦 ⟩
11 1 cv ⊢ 𝑤
12 10 11 wcel ⊢ ⟨ ⟨ 𝑧 , 𝑥 ⟩ , 𝑦 ⟩ ∈ 𝑤
13 12 3 4 5 coprab ⊢ { ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∣ ⟨ ⟨ 𝑧 , 𝑥 ⟩ , 𝑦 ⟩ ∈ 𝑤 }
14 1 2 13 cmpt ⊢ ( 𝑤 ∈ V ↦ { ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∣ ⟨ ⟨ 𝑧 , 𝑥 ⟩ , 𝑦 ⟩ ∈ 𝑤 } )
15 0 14 wceq ⊢ Cnv2 = ( 𝑤 ∈ V ↦ { ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∣ ⟨ ⟨ 𝑧 , 𝑥 ⟩ , 𝑦 ⟩ ∈ 𝑤 } )