Why is Euler's number an uppercase "E" and not a lowercase "e"?

Isn't Euler's Number normally expressed with a lowercase "e"?

  • 6
    $\begingroup$ All MM-defined symbols start with uppercase $\endgroup$ Commented Sep 11, 2012 at 6:37
  • 4
    $\begingroup$ No need to downvote, guys. $\endgroup$ Commented Sep 11, 2012 at 6:39
  • 5
    $\begingroup$ You can also typeset it with Esc + ee + Esc... $\endgroup$
    – Yves Klett
    Commented Sep 11, 2012 at 8:07
  • 1
    $\begingroup$ ...or enter \[ExponentialE] directly. $\endgroup$ Commented Sep 11, 2012 at 8:40
  • $\begingroup$ And note that the 'e' you obtain from Esc + ee + Esc or from \[ExponentialE] has a doubled stroke on its left, as do the corresponding symbols from \[ImaginaryI] and [\DifferentialD] -- akin to the "blackboard bold" font commonly used in typesetting mathematical documents (e.g., with LaTeX). $\endgroup$
    – murray
    Commented Sep 12, 2012 at 15:07

1 Answer 1


As often happens here, the comment provides the answer, but here's the answer from Stephen Wolfram's book about Mathematica (the second edition of "Mathematica, a System for Doing Mathematics by Computer" which I bought for £0.01 on Amazon):

Mathematica uses both upper- and lower-case letters. There is a convention that built-in Mathematica objects always have names starting with upper-case (capital) letters. To avoid confusion, you should always choose names for your own variables that start with lower-case letters.

This means that you can use e, i, n, or even sin or pi for your own variables without conflicting with Mathematica's constants and functions.

  • $\begingroup$ Closed? "We expect answers to be supported by facts, references, or specific expertise, but this question will likely solicit debate, arguments, polling, or extended discussion." you're joking, surely... :) $\endgroup$
    – cormullion
    Commented Sep 11, 2012 at 15:34
  • $\begingroup$ I agree, your answer clearly involves a fact. Reopened the question. It seemed to be close to being reopened anyway. $\endgroup$ Commented Sep 11, 2012 at 19:20
  • $\begingroup$ @SjoerdC.deVries Thanks, I wouldn't have bothered, but this was the first question I've been able to answer for ages :) $\endgroup$
    – cormullion
    Commented Sep 11, 2012 at 19:33
  • $\begingroup$ Just to explain my vote, I saw this from the review page which does not show the answers. So only the question, which was not really a serious/useful one, was shown with 4 close votes already. Also, the comments seemed to have explained it well, so I cast the final vote. Probably wouldn't have voted had I seen your answer, but someone else would've cast the final one :) $\endgroup$
    – rm -rf
    Commented Sep 11, 2012 at 21:46
  • $\begingroup$ @R.M No worries - I'm just being curmudgeonly today... It wasn't much of a question, true, but then it's no worse than this one :) $\endgroup$
    – cormullion
    Commented Sep 11, 2012 at 22:25

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.