Definition df-n0 4535

Description: Define the set of nonnegative integers.

Assertion

Ref	Expression
df-n0	|- NN0 = (NN u. {0})

Detailed syntax breakdown of Definition df-n0

Step	Hyp	Ref	Expression
1		cn0 4094	. 2 class NN0
2		cn 4093	. . 3 class NN
3		cc0 4028	. . . 4 class 0
4	3	csn 1808	. . 3 class {0}
5	2, 4	cun 1485	. 2 class (NN u. {0})
6	1, 5	wceq 1091	1 wff NN0 = (NN u. {0})

This definition is referenced by:  elnn0 4536  nnssnn0 4537  nn0ssre 4538  nn0ssz 4578

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