Definition df-9 4469

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 4461	. 2 class 9
2		c8 4460	. . 3 class 8
3		c1 4029	. . 3 class 1
4		caddc 4031	. . 3 class +
5	2, 3, 4	co 3001	. 2 class (8 + 1)
6	1, 5	wceq 1091	1 wff 9 = (8 + 1)

This definition is referenced by:  9re 4478  9pos 4486  5p4e9 4499  6p3e9 4501  7p2e9 4502

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