Definition df-n0 8289

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 8288	. 2 class ℕ0
2		cn 8039	. . 3 class ℕ
3		cc0 6981	. . . 4 class 0
4	3	csn 3398	. . 3 class {0}
5	2, 4	cun 2971	. 2 class (ℕ ∪ {0})
6	1, 5	wceq 1284	1 wff ℕ0 = (ℕ ∪ {0})

This definition is referenced by:  elnn0  8290  nnssnn0  8291  nn0ssre  8292  nn0ex  8294  dfn2  8301  nn0addcl  8323  nn0mulcl  8324  nn0ssz  8369