Definition df-n0 9569

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 9568	. 2 class ℕ0
2		cn 9307	. . 3 class ℕ
3		cc0 8180	. . . 4 class 0
4	3	csn 3709	. . 3 class {0}
5	2, 4	cun 3218	. 2 class (ℕ ∪ {0})
6	1, 5	wceq 1402	1 wff ℕ0 = (ℕ ∪ {0})

This definition is used by:  elnn0  9570  nnssnn0  9571  nn0ssre  9572  nn0ex  9574  dfn2  9581  nn0addcl  9603  nn0mulcl  9604  nn0ssz  9667  dvdsprmpweqnn  13138