What is the difference between ‍‍\ldots‎ and ‎\cdots‎?

For example, To write a sequence of points which is best to use? a_1,\ldots,a_n Or a_1,\cdots,a_n.

Couple of examples of the difference can be useful.

  • 3
    possible duplicate of \dots versus \ldots - is there a difference? – m0nhawk Jun 5 '13 at 10:26
  • 4
    Load amsmath and use \dots; in the vast majority of cases, the result will be what's usually found in mathematical publications. – egreg Jun 5 '13 at 10:28
  • 6
    Please do not vote so soon to close a question. The questioner should have the chance to respond to comments. It is better to initially ask whether the potential duplicate answers their question. – Andrew Swann Jun 5 '13 at 10:44

Although I agree with egreg's comment, the difference is mainly of an aesthetic nature imo. It depends on the context which version to use, which is also how amsmath decides which to use.

Some examples:

a_1,\ldots,a_n aligns better than a_1,\cdots,a_n.

But a_1 \to \ldots \to a_n aligns worse than a_1 \to \cdots \to a_n.

The alignment chosen by amsmath is usually the one commonly found in mathematical articles. However, I guess its not really wrong or anything to deviate from it.

enter image description here

  • 1
    while some authors may deviate from the "usual" pattern, a copyeditor trained in math tradition will mark deviations except in very special cases. amsmath was constructed to follow traditional typographic usage (which is, as noted, based largely on alignment, to avoid calling attention to its appearance and thus away from the underlying meaning). – barbara beeton Jun 5 '13 at 12:28
  • 1
    I am told that the standard practice is to use \ldots when the separator symbol is bottom-aligned (eg: comma ) and to use \cdots when the separator symbol is at center-aligned (eg: \to) – Cyriac Antony Aug 8 '19 at 5:50

Idots are used between the comma's (at the bottom) where as cdots are used between mostly in plus minus signs (at the middle of the line).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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