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 ) |