Description: The restriction of the identity relation to a set is a set. (Contributed by AV, 15-Feb-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | resiexd.b | |- ( ph -> B e. V ) |
|
| Assertion | resiexd | |- ( ph -> ( _I |` B ) e. _V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | resiexd.b | |- ( ph -> B e. V ) |
|
| 2 | funi | |- Fun _I |
|
| 3 | resfunexg | |- ( ( Fun _I /\ B e. V ) -> ( _I |` B ) e. _V ) |
|
| 4 | 2 1 3 | sylancr | |- ( ph -> ( _I |` B ) e. _V ) |