Definition df-3o 6693

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 6686	. 2 class 3o
2		c2o 6685	. . 3 class 2o
3	2	csuc 4512	. 2 class suc 2o
4	1, 3	wceq 1402	1 wff 3o = suc 2o

This definition is used by:  3on  6702  3onn  6799  pw1ne3  7596  pw1nel3  7597  sucpw1nel3  7599  3nelsucpw1  7600  3nsssucpw1  7602  onntri35  7603  hash3  11277  3dom  17235