Metamath Proof Explorer


Definition df-gdiv

Description: Define a function that maps a group operation to the group's division (or subtraction) operation. (Contributed by NM, 15-Feb-2008) (New usage is discouraged.)

Ref Expression
Assertion df-gdiv
|- /g = ( g e. GrpOp |-> ( x e. ran g , y e. ran g |-> ( x g ( ( inv ` g ) ` y ) ) ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cgs
 |-  /g
1 vg
 |-  g
2 cgr
 |-  GrpOp
3 vx
 |-  x
4 1 cv
 |-  g
5 4 crn
 |-  ran g
6 vy
 |-  y
7 3 cv
 |-  x
8 cgn
 |-  inv
9 4 8 cfv
 |-  ( inv ` g )
10 6 cv
 |-  y
11 10 9 cfv
 |-  ( ( inv ` g ) ` y )
12 7 11 4 co
 |-  ( x g ( ( inv ` g ) ` y ) )
13 3 6 5 5 12 cmpo
 |-  ( x e. ran g , y e. ran g |-> ( x g ( ( inv ` g ) ` y ) ) )
14 1 2 13 cmpt
 |-  ( g e. GrpOp |-> ( x e. ran g , y e. ran g |-> ( x g ( ( inv ` g ) ` y ) ) ) )
15 0 14 wceq
 |-  /g = ( g e. GrpOp |-> ( x e. ran g , y e. ran g |-> ( x g ( ( inv ` g ) ` y ) ) ) )