Metamath Proof Explorer


Theorem fnpr2o

Description: Function with a domain of 2o . (Contributed by Jim Kingdon, 25-Sep-2023)

Ref Expression
Assertion fnpr2o
|- ( ( A e. V /\ B e. W ) -> { <. (/) , A >. , <. 1o , B >. } Fn 2o )

Proof

Step Hyp Ref Expression
1 peano1
 |-  (/) e. _om
2 1 a1i
 |-  ( ( A e. V /\ B e. W ) -> (/) e. _om )
3 1onn
 |-  1o e. _om
4 3 a1i
 |-  ( ( A e. V /\ B e. W ) -> 1o e. _om )
5 simpl
 |-  ( ( A e. V /\ B e. W ) -> A e. V )
6 simpr
 |-  ( ( A e. V /\ B e. W ) -> B e. W )
7 1n0
 |-  1o =/= (/)
8 7 necomi
 |-  (/) =/= 1o
9 8 a1i
 |-  ( ( A e. V /\ B e. W ) -> (/) =/= 1o )
10 fnprg
 |-  ( ( ( (/) e. _om /\ 1o e. _om ) /\ ( A e. V /\ B e. W ) /\ (/) =/= 1o ) -> { <. (/) , A >. , <. 1o , B >. } Fn { (/) , 1o } )
11 2 4 5 6 9 10 syl221anc
 |-  ( ( A e. V /\ B e. W ) -> { <. (/) , A >. , <. 1o , B >. } Fn { (/) , 1o } )
12 df2o3
 |-  2o = { (/) , 1o }
13 12 fneq2i
 |-  ( { <. (/) , A >. , <. 1o , B >. } Fn 2o <-> { <. (/) , A >. , <. 1o , B >. } Fn { (/) , 1o } )
14 11 13 sylibr
 |-  ( ( A e. V /\ B e. W ) -> { <. (/) , A >. , <. 1o , B >. } Fn 2o )