Definition df-3o 6421

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 6414	. 2 class 3o
2		c2o 6413	. . 3 class 2o
3	2	csuc 4367	. 2 class suc 2o
4	1, 3	wceq 1353	1 wff 3o = suc 2o

This definition is referenced by:  3on  6430  3onn  6525  pw1ne3  7231  pw1nel3  7232  sucpw1nel3  7234  3nelsucpw1  7235  3nsssucpw1  7237  onntri35  7238  hash3  10795