Metamath Proof Explorer


Definition df-resc

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 >. ) )

Detailed syntax breakdown

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 >. ) )