Definition df-n0 9106

Description: Define the set of nonnegative integers. (Contributed by Raph Levien, 10-Dec-2002.)

Assertion

Ref	Expression
df-n0	⊢ ℕ0 = (ℕ ∪ {0})

Detailed syntax breakdown of Definition df-n0

Step	Hyp	Ref	Expression
1		cn0 9105	. 2 class ℕ0
2		cn 8848	. . 3 class ℕ
3		cc0 7744	. . . 4 class 0
4	3	csn 3570	. . 3 class {0}
5	2, 4	cun 3109	. 2 class (ℕ ∪ {0})
6	1, 5	wceq 1342	1 wff ℕ0 = (ℕ ∪ {0})

This definition is referenced by:  elnn0  9107  nnssnn0  9108  nn0ssre  9109  nn0ex  9111  dfn2  9118  nn0addcl  9140  nn0mulcl  9141  nn0ssz  9200  dvdsprmpweqnn  12244