Metamath Proof Explorer


Theorem nn0expcl

Description: Closure of exponentiation of nonnegative integers. (Contributed by NM, 14-Dec-2005)

Ref Expression
Assertion nn0expcl A 0 N 0 A N 0

Proof

Step Hyp Ref Expression
1 nn0sscn 0
2 nn0mulcl x 0 y 0 x y 0
3 1nn0 1 0
4 1 2 3 expcllem A 0 N 0 A N 0