Metamath Proof Explorer


Theorem nn0absidi

Description: A nonnegative integer is its own absolute value (inference form). (Contributed by AV, 22-Nov-2025)

Ref Expression
Hypothesis nn0absidi.i
|- N e. NN0
Assertion nn0absidi
|- ( abs ` N ) = N

Proof

Step Hyp Ref Expression
1 nn0absidi.i
 |-  N e. NN0
2 nn0absid
 |-  ( N e. NN0 -> ( abs ` N ) = N )
3 1 2 ax-mp
 |-  ( abs ` N ) = N