Definition df-3o 6570

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 6563	. 2 class 3o
2		c2o 6562	. . 3 class 2o
3	2	csuc 4456	. 2 class suc 2o
4	1, 3	wceq 1395	1 wff 3o = suc 2o

This definition is referenced by:  3on  6579  3onn  6676  pw1ne3  7423  pw1nel3  7424  sucpw1nel3  7426  3nelsucpw1  7427  3nsssucpw1  7429  onntri35  7430  hash3  11043  3dom  16381