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 ) ) ) ) |
| 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 ) ) ) ) |