Description: A terminal object is an object. (Contributed by AV, 18-Apr-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | termoo | |- ( C e. Cat -> ( O e. ( TermO ` C ) -> O e. ( Base ` C ) ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | eqid | |- ( Base ` C ) = ( Base ` C ) | |
| 2 | eqid | |- ( Hom ` C ) = ( Hom ` C ) | |
| 3 | id | |- ( C e. Cat -> C e. Cat ) | |
| 4 | 1 2 3 | istermoi | |- ( ( C e. Cat /\ O e. ( TermO ` C ) ) -> ( O e. ( Base ` C ) /\ A. b e. ( Base ` C ) E! h h e. ( b ( Hom ` C ) O ) ) ) | 
| 5 | 4 | simpld | |- ( ( C e. Cat /\ O e. ( TermO ` C ) ) -> O e. ( Base ` C ) ) | 
| 6 | 5 | ex | |- ( C e. Cat -> ( O e. ( TermO ` C ) -> O e. ( Base ` C ) ) ) |