Metamath Proof Explorer


Definition df-gdlop5

Description: Define the fifth Gödel operation. This function takes two arguments and returns the intersection of the first argument with the domain of the second argument (see df-in and df-dm ). Based on the fifth case of Definition 14.2 of TakeutiZaring p. 144. (Contributed by BTernaryTau, 2-Sep-2026)

Ref Expression
Assertion df-gdlop5 ℱ5 = ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ( 𝑥 ∩ dom 𝑦 ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cgdlop5 ⊢ ℱ5
1 vx ⊢ 𝑥
2 cvv ⊢ V
3 vy ⊢ 𝑦
4 1 cv ⊢ 𝑥
5 3 cv ⊢ 𝑦
6 5 cdm ⊢ dom 𝑦
7 4 6 cin ⊢ ( 𝑥 ∩ dom 𝑦 )
8 1 3 2 2 7 cmpo ⊢ ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ( 𝑥 ∩ dom 𝑦 ) )
9 0 8 wceq ⊢ ℱ5 = ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ( 𝑥 ∩ dom 𝑦 ) )