Description: Ordered pair membership in the class of complex numbers. (Contributed by NM, 14-May-1996) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | opelcn | |- ( <. A , B >. e. CC <-> ( A e. R. /\ B e. R. ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | df-c | |- CC = ( R. X. R. ) | |
| 2 | 1 | eleq2i | |- ( <. A , B >. e. CC <-> <. A , B >. e. ( R. X. R. ) ) | 
| 3 | opelxp | |- ( <. A , B >. e. ( R. X. R. ) <-> ( A e. R. /\ B e. R. ) ) | |
| 4 | 2 3 | bitri | |- ( <. A , B >. e. CC <-> ( A e. R. /\ B e. R. ) ) |