Definition df-3o 6554

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 6547	. 2 class 3o
2		c2o 6546	. . 3 class 2o
3	2	csuc 4453	. 2 class suc 2o
4	1, 3	wceq 1395	1 wff 3o = suc 2o

This definition is referenced by:  3on  6563  3onn  6658  pw1ne3  7403  pw1nel3  7404  sucpw1nel3  7406  3nelsucpw1  7407  3nsssucpw1  7409  onntri35  7410  hash3  11022