Metamath Proof Explorer


Definition df-abs

Description: Define the function for the absolute value (modulus) of a complex number. See abscli for its closure and absval or absval2i for its value. For example, ( abs-u 2 ) = 2 ( ex-abs ). (Contributed by NM, 27-Jul-1999)

Ref Expression
Assertion df-abs abs = x x x

Detailed syntax breakdown

Step Hyp Ref Expression
0 cabs class abs
1 vx setvar x
2 cc class
3 csqrt class
4 1 cv setvar x
5 cmul class ×
6 ccj class *
7 4 6 cfv class x
8 4 7 5 co class x x
9 8 3 cfv class x x
10 1 2 9 cmpt class x x x
11 0 10 wceq wff abs = x x x