Definition df-3o 6689

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 6682	. 2 class 3o
2		c2o 6681	. . 3 class 2o
3	2	csuc 4510	. 2 class suc 2o
4	1, 3	wceq 1402	1 wff 3o = suc 2o

This definition is used by:  3on  6698  3onn  6795  pw1ne3  7590  pw1nel3  7591  sucpw1nel3  7593  3nelsucpw1  7594  3nsssucpw1  7596  onntri35  7597  hash3  11269  3dom  17140