Description: Binary relation for an ordered pair singleton. (Contributed by Thierry Arnoux, 23-Sep-2023)
Ref | Expression | ||
---|---|---|---|
Assertion | brsnop | |- ( ( A e. V /\ B e. W ) -> ( X { <. A , B >. } Y <-> ( X = A /\ Y = B ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-br | |- ( X { <. A , B >. } Y <-> <. X , Y >. e. { <. A , B >. } ) |
|
2 | opex | |- <. X , Y >. e. _V |
|
3 | 2 | elsn | |- ( <. X , Y >. e. { <. A , B >. } <-> <. X , Y >. = <. A , B >. ) |
4 | opthg2 | |- ( ( A e. V /\ B e. W ) -> ( <. X , Y >. = <. A , B >. <-> ( X = A /\ Y = B ) ) ) |
|
5 | 3 4 | syl5bb | |- ( ( A e. V /\ B e. W ) -> ( <. X , Y >. e. { <. A , B >. } <-> ( X = A /\ Y = B ) ) ) |
6 | 1 5 | syl5bb | |- ( ( A e. V /\ B e. W ) -> ( X { <. A , B >. } Y <-> ( X = A /\ Y = B ) ) ) |