Definition df-3o 6584

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 6577	. 2 class 3o
2		c2o 6576	. . 3 class 2o
3	2	csuc 4462	. 2 class suc 2o
4	1, 3	wceq 1397	1 wff 3o = suc 2o

This definition is referenced by:  3on  6593  3onn  6690  pw1ne3  7448  pw1nel3  7449  sucpw1nel3  7451  3nelsucpw1  7452  3nsssucpw1  7454  onntri35  7455  hash3  11078  3dom  16613