Description: 1 is a nonnegative integer. (Contributed by Raph Levien, 10-Dec-2002)
Ref | Expression | ||
---|---|---|---|
Assertion | 1nn0 | $${\u22a2}1\in {\mathbb{N}}_{0}$$ |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 1nn | $${\u22a2}1\in \mathbb{N}$$ | |
2 | 1 | nnnn0i | $${\u22a2}1\in {\mathbb{N}}_{0}$$ |