Metamath Proof Explorer


Definition df-image

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 𝖨𝗆𝖺𝗀𝖾 A = V × V ran V E E A -1 V

Detailed syntax breakdown

Step Hyp Ref Expression
0 cA class A
1 0 cimage class 𝖨𝗆𝖺𝗀𝖾 A
2 cvv class V
3 2 2 cxp class V × V
4 cep class E
5 2 4 ctxp class V E
6 0 ccnv class A -1
7 4 6 ccom class E A -1
8 7 2 ctxp class E A -1 V
9 5 8 csymdif class V E E A -1 V
10 9 crn class ran V E E A -1 V
11 3 10 cdif class V × V ran V E E A -1 V
12 1 11 wceq wff 𝖨𝗆𝖺𝗀𝖾 A = V × V ran V E E A -1 V