Definition df-e 11960

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 11954	. 2 class _e
2		c1 7926	. . 3 class 1
3		ce 11953	. . 3 class exp
4	2, 3	cfv 5271	. 2 class ( exp ` 1 )
5	1, 4	wceq 1373	1 wff _e = ( exp ` 1 )

This definition is referenced by:  esum  11973  ere  11981  ege2le3  11982  efzval  11994  reeff1oleme  15244  loge  15339  logdivlti  15353