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 | bitrid |  |-  ( ( A e. V /\ B e. W ) -> ( <. X , Y >. e. { <. A , B >. } <-> ( X = A /\ Y = B ) ) ) | 
| 6 | 1 5 | bitrid |  |-  ( ( A e. V /\ B e. W ) -> ( X { <. A , B >. } Y <-> ( X = A /\ Y = B ) ) ) |