11

I want to have a primed product symbol, i.e. something like

$\prod^\prime$

but it puts the prime on top of the product symbol instead of next to it (as a superscript, as it usually works). Does anyone know how to do this?

B. Pasternak
  • 605
  • 1
    Just curious, is it a conventional notation, or your own thing? And what does it stand for? – Jeon Oct 02 '16 at 21:08
  • The notation is introduced by my teacher in a homework assignment to denote a product which only runs till a certainly value. Of course, one should just use the natural limits that come with \prod, but I guess everyone has its own way. – B. Pasternak Oct 02 '16 at 21:18

2 Answers2

19

The amsmath package has a \sideset command for this purpose:

Sample output

\documentclass{article}

\usepackage{amsmath}

\begin{document}

\begin{equation*}
  \sideset{}{'}\prod_{n=-k}^k \frac{a_n}{n}
\end{equation*}

\end{document}

The general syntax is 

\sideset{_a^b}{_c^d}\sum

producing

Full sample

and works on any large operator \prod, \sum, etc.

Andrew Swann
  • 95,762
2

You have to detach the superscript from the operator. Below I've inserted a \vphantom that is the size of \prod:

enter image description here

\documentclass{article}

\begin{document}

\[
  \prod_{i=0}^n f_i \quad \prod{\vphantom\prod}'
\]

\end{document}
Werner
  • 603,163
  • Why not ${\prod}'$? (Actually it seems that even $\prod^\prime$ no longer produces the behaviour described in the post, so maybe you were dealing with some necessity that 4 years has removed.) – LSpice Jul 18 '20 at 17:25