Definition df-9 5979

Description: Define the number 9.

Assertion

Ref	Expression
df-9	|- 9 = (8 + 1)

Detailed syntax breakdown of Definition df-9

Step	Hyp	Ref	Expression
1		c9 5970	. 2 class 9
2		c8 5969	. . 3 class 8
3		c1 5247	. . 3 class 1
4		caddc 5249	. . 3 class +
5	2, 3, 4	co 3969	. 2 class (8 + 1)
6	1, 5	wceq 958	1 wff 9 = (8 + 1)

This definition is referenced by:  9re 5989  9pos 5999  5p4e9 6016  6p3e9 6019  7p2e9 6021  8p2e10 6023  cos2bnd 7476

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