Definition df-e 12360

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 12354	. 2 class _e
2		c1 8144	. . 3 class 1
3		ce 12353	. . 3 class exp
4	2, 3	cfv 5357	. 2 class ( exp ` 1 )
5	1, 4	wceq 1398	1 wff _e = ( exp ` 1 )

This definition is referenced by:  esum  12373  ere  12381  ege2le3  12382  efzval  12394  reeff1oleme  15763  loge  15858  logdivlti  15872