Definition df-3o 6679

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 6672	. 2 class 3o
2		c2o 6671	. . 3 class 2o
3	2	csuc 4505	. 2 class suc 2o
4	1, 3	wceq 1402	1 wff 3o = suc 2o

This definition is referenced by:  3on  6688  3onn  6785  pw1ne3  7579  pw1nel3  7580  sucpw1nel3  7582  3nelsucpw1  7583  3nsssucpw1  7585  onntri35  7586  hash3  11232  3dom  16932