Description: The subcategory subset relation is reflexive. (Contributed by Mario Carneiro, 6-Jan-2017)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | sscid | |- ( ( H Fn ( S X. S ) /\ S e. V ) -> H C_cat H ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | fnresdm | |- ( H Fn ( S X. S ) -> ( H |` ( S X. S ) ) = H ) | |
| 2 | 1 | adantr | |- ( ( H Fn ( S X. S ) /\ S e. V ) -> ( H |` ( S X. S ) ) = H ) | 
| 3 | sscres | |- ( ( H Fn ( S X. S ) /\ S e. V ) -> ( H |` ( S X. S ) ) C_cat H ) | |
| 4 | 2 3 | eqbrtrrd | |- ( ( H Fn ( S X. S ) /\ S e. V ) -> H C_cat H ) |