Theorem absidi

Description: A nonnegative number is its own absolute value. (Contributed by NM, 2-Aug-1999)

	Ref	Expression
Hypothesis	sqrtthi.1	|- A e. RR
Assertion	absidi	|- ( 0 <_ A -> ( abs ` A ) = A )

Proof

Step	Hyp	Ref	Expression
1		sqrtthi.1	|- A e. RR
2		absid	|- ( ( A e. RR /\ 0 <_ A ) -> ( abs ` A ) = A )
3	1 2	mpan	|- ( 0 <_ A -> ( abs ` A ) = A )