Definition df-xnn0 12626

Description: Define the set of extended nonnegative integers that includes positive infinity. Analogue of the extension of the real numbers ℝ^*, see df-xr 11328. (Contributed by AV, 10-Dec-2020.)

Assertion

Ref	Expression
df-xnn0	⊢ ℕ0* = (ℕ0 ∪ {+∞})

Detailed syntax breakdown of Definition df-xnn0

Step	Hyp	Ref	Expression
1		cxnn0 12625	. 2 class ℕ0*
2		cn0 12553	. . 3 class ℕ0
3		cpnf 11321	. . . 4 class +∞
4	3	csn 4648	. . 3 class {+∞}
5	2, 4	cun 3974	. 2 class (ℕ0 ∪ {+∞})
6	1, 5	wceq 1537	1 wff ℕ0* = (ℕ0 ∪ {+∞})

This definition is referenced by:  elxnn0  12627  nn0ssxnn0  12628  hashfxnn0  14386  hashf  14387