Metamath Proof Explorer


Theorem gdlop1fv

Description: The value of the first Gödel operation. (Contributed by BTernaryTau, 18-Oct-2026)

Ref Expression
Hypotheses gdlop1fv.1 ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 )
gdlop1fv.2 ⊢ ( 𝜑 → 𝐵 ∈ 𝑊 )
Assertion gdlop1fv ( 𝜑 → ( ℱ1 ‘ ⟨ 𝐴 , 𝐵 ⟩ ) = { 𝐴 , 𝐵 } )

Proof

Step Hyp Ref Expression
1 gdlop1fv.1 ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 )
2 gdlop1fv.2 ⊢ ( 𝜑 → 𝐵 ∈ 𝑊 )
3 1 elexd ⊢ ( 𝜑 → 𝐴 ∈ V )
4 2 elexd ⊢ ( 𝜑 → 𝐵 ∈ V )
5 prex ⊢ { 𝐴 , 𝐵 } ∈ V
6 5 a1i ⊢ ( 𝜑 → { 𝐴 , 𝐵 } ∈ V )
7 preq1 ⊢ ( 𝐴 = 𝑥 → { 𝐴 , 𝑦 } = { 𝑥 , 𝑦 } )
8 7 adantl ⊢ ( ( 𝜑 ∧ 𝐴 = 𝑥 ) → { 𝐴 , 𝑦 } = { 𝑥 , 𝑦 } )
9 preq2 ⊢ ( 𝐵 = 𝑦 → { 𝐴 , 𝐵 } = { 𝐴 , 𝑦 } )
10 9 adantl ⊢ ( ( 𝜑 ∧ 𝐵 = 𝑦 ) → { 𝐴 , 𝐵 } = { 𝐴 , 𝑦 } )
11 df-gdlop1 ⊢ ℱ1 = ( 𝑥 ∈ V , 𝑦 ∈ V ↦ { 𝑥 , 𝑦 } )
12 3 4 6 8 10 11 mpofvop2d ⊢ ( 𝜑 → ( ℱ1 ‘ ⟨ 𝐴 , 𝐵 ⟩ ) = { 𝐴 , 𝐵 } )