Definition df-1o 6001

Description: Define the ordinal number 1. (Contributed by NM, 29-Oct-1995.)

Assertion

Ref	Expression
df-1o	⊢ 1𝑜 = suc ∅

Detailed syntax breakdown of Definition df-1o

Step	Hyp	Ref	Expression
1		c1o 5994	. 2 class 1𝑜
2		c0 3224	. . 3 class ∅
3	2	csuc 4102	. 2 class suc ∅
4	1, 3	wceq 1243	1 wff 1𝑜 = suc ∅

This definition is referenced by:  1on  6008  df1o2  6013  ordgt0ge1  6018  oa1suc  6047  1onn  6093  nnm1  6097  nlt1pig  6439  indpi  6440