Definition df-4

Description: Define the number 4. (Contributed by NM, 27-May-1999)

	Ref	Expression
Assertion	df-4	⊢ 4 = ( 3 + 1 )

Detailed syntax breakdown

Step	Hyp	Ref	Expression
0		c4	⊢ 4
1		c3	⊢ 3
2		caddc	⊢ +
3		c1	⊢ 1
4	1 3 2	co	⊢ ( 3 + 1 )
5	0 4	wceq	⊢ 4 = ( 3 + 1 )