Description: Define the image functor. This function takes a set A to a function x |-> ( A " x ) , providing that the latter exists. See imageval for the derivation. (Contributed by Scott Fenton, 27-Mar-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | df-image | |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cA | |
|
1 | 0 | cimage | |
2 | cvv | |
|
3 | 2 2 | cxp | |
4 | cep | |
|
5 | 2 4 | ctxp | |
6 | 0 | ccnv | |
7 | 4 6 | ccom | |
8 | 7 2 | ctxp | |
9 | 5 8 | csymdif | |
10 | 9 | crn | |
11 | 3 10 | cdif | |
12 | 1 11 | wceq | |