Metamath Proof Explorer


Definition df-re

Description: Define a function whose value is the real part of a complex number. See reval for its value, recli for its closure, and replim for its use in decomposing a complex number. (Contributed by NM, 9-May-1999)

Ref Expression
Assertion df-re = x x + x 2

Detailed syntax breakdown

Step Hyp Ref Expression
0 cre class
1 vx setvar x
2 cc class
3 1 cv setvar x
4 caddc class +
5 ccj class *
6 3 5 cfv class x
7 3 6 4 co class x + x
8 cdiv class ÷
9 c2 class 2
10 7 9 8 co class x + x 2
11 1 2 10 cmpt class x x + x 2
12 0 11 wceq wff = x x + x 2