Metamath Proof Explorer


Definition df-ghomOLD

Description: Obsolete version of df-ghm as of 15-Mar-2020. Define the set of group homomorphisms from g to h . (Contributed by Paul Chapman, 25-Feb-2008) (New usage is discouraged.)

Ref Expression
Assertion df-ghomOLD
|- GrpOpHom = ( g e. GrpOp , h e. GrpOp |-> { f | ( f : ran g --> ran h /\ A. x e. ran g A. y e. ran g ( ( f ` x ) h ( f ` y ) ) = ( f ` ( x g y ) ) ) } )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cghomOLD
 |-  GrpOpHom
1 vg
 |-  g
2 cgr
 |-  GrpOp
3 vh
 |-  h
4 vf
 |-  f
5 4 cv
 |-  f
6 1 cv
 |-  g
7 6 crn
 |-  ran g
8 3 cv
 |-  h
9 8 crn
 |-  ran h
10 7 9 5 wf
 |-  f : ran g --> ran h
11 vx
 |-  x
12 vy
 |-  y
13 11 cv
 |-  x
14 13 5 cfv
 |-  ( f ` x )
15 12 cv
 |-  y
16 15 5 cfv
 |-  ( f ` y )
17 14 16 8 co
 |-  ( ( f ` x ) h ( f ` y ) )
18 13 15 6 co
 |-  ( x g y )
19 18 5 cfv
 |-  ( f ` ( x g y ) )
20 17 19 wceq
 |-  ( ( f ` x ) h ( f ` y ) ) = ( f ` ( x g y ) )
21 20 12 7 wral
 |-  A. y e. ran g ( ( f ` x ) h ( f ` y ) ) = ( f ` ( x g y ) )
22 21 11 7 wral
 |-  A. x e. ran g A. y e. ran g ( ( f ` x ) h ( f ` y ) ) = ( f ` ( x g y ) )
23 10 22 wa
 |-  ( f : ran g --> ran h /\ A. x e. ran g A. y e. ran g ( ( f ` x ) h ( f ` y ) ) = ( f ` ( x g y ) ) )
24 23 4 cab
 |-  { f | ( f : ran g --> ran h /\ A. x e. ran g A. y e. ran g ( ( f ` x ) h ( f ` y ) ) = ( f ` ( x g y ) ) ) }
25 1 3 2 2 24 cmpo
 |-  ( g e. GrpOp , h e. GrpOp |-> { f | ( f : ran g --> ran h /\ A. x e. ran g A. y e. ran g ( ( f ` x ) h ( f ` y ) ) = ( f ` ( x g y ) ) ) } )
26 0 25 wceq
 |-  GrpOpHom = ( g e. GrpOp , h e. GrpOp |-> { f | ( f : ran g --> ran h /\ A. x e. ran g A. y e. ran g ( ( f ` x ) h ( f ` y ) ) = ( f ` ( x g y ) ) ) } )