Definition df-3o 6026

Description: Define the ordinal number 3. (Contributed by Mario Carneiro, 14-Jul-2013.)

Assertion

Ref	Expression
df-3o	⊢ 3𝑜 = suc 2𝑜

Detailed syntax breakdown of Definition df-3o

Step	Hyp	Ref	Expression
1		c3o 6019	. 2 class 3𝑜
2		c2o 6018	. . 3 class 2𝑜
3	2	csuc 4120	. 2 class suc 2𝑜
4	1, 3	wceq 1284	1 wff 3𝑜 = suc 2𝑜

This definition is referenced by:  3on  6034  3onn  6118