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Definition df-xnn0 11402
Description: Define the set of extended nonnegative integers that includes positive infinity. Analogue of the extension of the real numbers *, see df-xr 10116. (Contributed by AV, 10-Dec-2020.)
Assertion
Ref Expression
df-xnn0 0* = (ℕ0 ∪ {+∞})

Detailed syntax breakdown of Definition df-xnn0
StepHypRef Expression
1 cxnn0 11401 . 2 class 0*
2 cn0 11330 . . 3 class 0
3 cpnf 10109 . . . 4 class +∞
43csn 4210 . . 3 class {+∞}
52, 4cun 3605 . 2 class (ℕ0 ∪ {+∞})
61, 5wceq 1523 1 wff 0* = (ℕ0 ∪ {+∞})
Colors of variables: wff setvar class
This definition is referenced by:  elxnn0  11403  nn0ssxnn0  11404  hashfxnn0  13164  hashf  13165
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