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 βŠ’π–¨π—†π–Ίπ—€π–ΎA=VΓ—Vβˆ–ran⁑VβŠ—Eβˆ†E∘A-1βŠ—V

Detailed syntax breakdown

Step Hyp Ref Expression
0 cA classA
1 0 cimage class𝖨𝗆𝖺𝗀𝖾A
2 cvv classV
3 2 2 cxp classVΓ—V
4 cep classE
5 2 4 ctxp classVβŠ—E
6 0 ccnv classA-1
7 4 6 ccom classE∘A-1
8 7 2 ctxp classE∘A-1βŠ—V
9 5 8 csymdif classVβŠ—Eβˆ†E∘A-1βŠ—V
10 9 crn classran⁑VβŠ—Eβˆ†E∘A-1βŠ—V
11 3 10 cdif classVΓ—Vβˆ–ran⁑VβŠ—Eβˆ†E∘A-1βŠ—V
12 1 11 wceq wff𝖨𝗆𝖺𝗀𝖾A=VΓ—Vβˆ–ran⁑VβŠ—Eβˆ†E∘A-1βŠ—V