Definition df-3o 6627

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 6620	. 2 class 3o
2		c2o 6619	. . 3 class 2o
3	2	csuc 4468	. 2 class suc 2o
4	1, 3	wceq 1398	1 wff 3o = suc 2o

This definition is referenced by:  3on  6636  3onn  6733  pw1ne3  7491  pw1nel3  7492  sucpw1nel3  7494  3nelsucpw1  7495  3nsssucpw1  7497  onntri35  7498  hash3  11121  3dom  16688