How to get slender \prod symbol in display mode

When I use \prod in math display mode it comes in darker form. How can I make it slender?

\documentclass[11pt,reqno,fleqn,a4paper]{article}
\usepackage{amsmath,amssymb,amsfonts}
\begin{document}
The following has product symbol in bold form $$\prod_{i=1}^{n}\bigcup_{\alpha} A_{\alpha_i}$$
\end{document}


If $...$ is used instead of $$...$$ for math display mode, I get the same result.

P.S. Here I said bold by the look of the font. I know there is a much darker version of this symbol in the bold symbol.

• Welcome to TeX.SX! Please help us (and also you) and add a minimal working example (MWE), that illustrates your problem. Reproducing the problem and finding out what the issue is will be much easier when we see compilable code, starting with \documentclass and ending with \end{document}. – Bobyandbob Sep 19 '17 at 13:27
• Do you mean it's bigger than in inline formulas? That's wanted. It's not “bold”. – egreg Sep 19 '17 at 13:28
• Off-topic but don't use $$...$$ for display maths in LaTeX. Use $...$ instead. (These are not equivalent.) – cfr Sep 19 '17 at 13:40
• @egreg I want it to be bigger in displaymode, but not bold like in the image given. – supremum Sep 19 '17 at 13:48
• @supremum It's not bold. Look at the top stroke. – egreg Sep 19 '17 at 13:50

That's the standard shape of the symbol and you'll find thick side bars in most books.

However, you can use the “concrete“ version of the symbol.

\documentclass{article}

% redefine \prod prior to amsmath doing its job
\DeclareSymbolFont{slenderlargesymbols}{OMX}{ccex}{m}{n}
\DeclareMathSymbol{\prod}{\mathop}{slenderlargesymbols}{"51}

\usepackage{amsmath,amssymb,amsfonts}

\begin{document}

The following has a slender product symbol
$\prod_{i=1}^{n}\bigcup_{\alpha} A_{\alpha_i}$

\end{document}


• It gives an error Command '\prod' already defined. ...l{\prod}{\mathop}{slenderlargesymbols}{"51} – supremum Sep 19 '17 at 14:07
• I have to use the packages too: \usepackage{amsmath,amssymb,amsfonts}. Without these packages your answer works fine for me. – supremum Sep 19 '17 at 14:09
• @supremum The redefinition of \prod has to be done prior to loading amsmath. See the updated answer. – egreg Sep 19 '17 at 14:14
• I liked. This could be the default symbol because I agree that the other is too dark. – Sigur Sep 19 '17 at 14:17