Metamath Proof Explorer

Theorem nn0re

Description: A nonnegative integer is a real number. (Contributed by NM, 9-May-2004)

Ref Expression
Assertion nn0re 
|- ( A e. NN0 -> A e. RR )

Proof

Step Hyp Ref Expression
1 nn0ssre 
 |-  NN0 C_ RR
2 1 sseli 
 |-  ( A e. NN0 -> A e. RR )