Definition df-3o 6575

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 6568	. 2 class 3o
2		c2o 6567	. . 3 class 2o
3	2	csuc 4457	. 2 class suc 2o
4	1, 3	wceq 1395	1 wff 3o = suc 2o

This definition is referenced by:  3on  6584  3onn  6681  pw1ne3  7431  pw1nel3  7432  sucpw1nel3  7434  3nelsucpw1  7435  3nsssucpw1  7437  onntri35  7438  hash3  11053  3dom  16465