Metamath Proof Explorer


Theorem gdlop1fv

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

Ref Expression
Hypotheses gdlop1fv.1
|- ( ph -> A e. V )
gdlop1fv.2
|- ( ph -> B e. W )
Assertion gdlop1fv
|- ( ph -> ( ~F1 ` <. A , B >. ) = { A , B } )

Proof

Step Hyp Ref Expression
1 gdlop1fv.1
 |-  ( ph -> A e. V )
2 gdlop1fv.2
 |-  ( ph -> B e. W )
3 1 elexd
 |-  ( ph -> A e. _V )
4 2 elexd
 |-  ( ph -> B e. _V )
5 prex
 |-  { A , B } e. _V
6 5 a1i
 |-  ( ph -> { A , B } e. _V )
7 preq1
 |-  ( A = x -> { A , y } = { x , y } )
8 7 adantl
 |-  ( ( ph /\ A = x ) -> { A , y } = { x , y } )
9 preq2
 |-  ( B = y -> { A , B } = { A , y } )
10 9 adantl
 |-  ( ( ph /\ B = y ) -> { A , B } = { A , y } )
11 df-gdlop1
 |-  ~F1 = ( x e. _V , y e. _V |-> { x , y } )
12 3 4 6 8 10 11 mpofvop2d
 |-  ( ph -> ( ~F1 ` <. A , B >. ) = { A , B } )