Metamath Proof Explorer


Definition df-staf

Description: Define the functionalization of the involution in a star ring. This is not strictly necessary but by having *r as an actual function we can state the principal properties of an involution much more cleanly. (Contributed by Mario Carneiro, 6-Oct-2015)

Ref Expression
Assertion df-staf 𝑟𝑓 = f V x Base f x * f

Detailed syntax breakdown

Step Hyp Ref Expression
0 cstf class 𝑟𝑓
1 vf setvar f
2 cvv class V
3 vx setvar x
4 cbs class Base
5 1 cv setvar f
6 5 4 cfv class Base f
7 cstv class 𝑟
8 5 7 cfv class * f
9 3 cv setvar x
10 9 8 cfv class x * f
11 3 6 10 cmpt class x Base f x * f
12 1 2 11 cmpt class f V x Base f x * f
13 0 12 wceq wff 𝑟𝑓 = f V x Base f x * f