Definition df-e 11814

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

Assertion

Ref	Expression
df-e	|- _e = ( exp ` 1 )

Detailed syntax breakdown of Definition df-e

Step	Hyp	Ref	Expression
1		ceu 11808	. 2 class _e
2		c1 7880	. . 3 class 1
3		ce 11807	. . 3 class exp
4	2, 3	cfv 5258	. 2 class ( exp ` 1 )
5	1, 4	wceq 1364	1 wff _e = ( exp ` 1 )

This definition is referenced by:  esum  11827  ere  11835  ege2le3  11836  efzval  11848  reeff1oleme  15008  loge  15103  logdivlti  15117