Metamath Proof Explorer

Theorem absnidi

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

Ref Expression
Hypothesis sqrtthi.1 A
Assertion absnidi A 0 A = A


Step Hyp Ref Expression
1 sqrtthi.1 A
2 absnid A A 0 A = A
3 1 2 mpan A 0 A = A