Definition df-e

Description: Define Euler's constant _e = 2.71828.... (Contributed by NM, 14-Mar-2005)

	Ref	Expression
Assertion	df-e	⊢ e = ( exp ‘ 1 )

Detailed syntax breakdown

Step	Hyp	Ref	Expression
0		ceu	⊢ e
1		ce	⊢ exp
2		c1	⊢ 1
3	2 1	cfv	⊢ ( exp ‘ 1 )
4	0 3	wceq	⊢ e = ( exp ‘ 1 )