Definition df-1o 6313

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 6306	. 2 class 1o
2		c0 3363	. . 3 class ∅
3	2	csuc 4287	. 2 class suc ∅
4	1, 3	wceq 1331	1 wff 1o = suc ∅

This definition is referenced by:  1on  6320  df1o2  6326  ordgt0ge1  6332  oa1suc  6363  1onn  6416  nnm1  6420  nlt1pig  7149  indpi  7150  1tonninf  10213  hash1  10557  pwle2  13193  isomninnlem  13225