Description: Define the restriction of a category to a given set of arrows. (Contributed by Mario Carneiro, 4-Jan-2017)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-resc | |- |`cat = ( c e. _V , h e. _V |-> ( ( c |`s dom dom h ) sSet <. ( Hom ` ndx ) , h >. ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | cresc | |- |`cat |
|
| 1 | vc | |- c |
|
| 2 | cvv | |- _V |
|
| 3 | vh | |- h |
|
| 4 | 1 | cv | |- c |
| 5 | cress | |- |`s |
|
| 6 | 3 | cv | |- h |
| 7 | 6 | cdm | |- dom h |
| 8 | 7 | cdm | |- dom dom h |
| 9 | 4 8 5 | co | |- ( c |`s dom dom h ) |
| 10 | csts | |- sSet |
|
| 11 | chom | |- Hom |
|
| 12 | cnx | |- ndx |
|
| 13 | 12 11 | cfv | |- ( Hom ` ndx ) |
| 14 | 13 6 | cop | |- <. ( Hom ` ndx ) , h >. |
| 15 | 9 14 10 | co | |- ( ( c |`s dom dom h ) sSet <. ( Hom ` ndx ) , h >. ) |
| 16 | 1 3 2 2 15 | cmpo | |- ( c e. _V , h e. _V |-> ( ( c |`s dom dom h ) sSet <. ( Hom ` ndx ) , h >. ) ) |
| 17 | 0 16 | wceq | |- |`cat = ( c e. _V , h e. _V |-> ( ( c |`s dom dom h ) sSet <. ( Hom ` ndx ) , h >. ) ) |