Whenever I use \cap in my tex, I get: enter image description here

(which I don't like) instead of:

enter image description here

Any way to produce the second intersection symbol? The same happens with \cup.

Edit: this is what I always use:

\DeclareMathOperator{\re}{Re }
\DeclareMathOperator{\im}{Im }

\newrefformat{fig}{la figura \ref{#1}}
\newrefformat{teo}{el teorema  \ref{#1}}
\newrefformat{lema}{el lema  \ref{#1}}
\newrefformat{prop}{la proposici\'on  \ref{#1}}
\newrefformat{coro}{el corolario  \ref{#1}}
\newrefformat{sec}{la secci\'on \ref{#1}}
\newrefformat{cap}{el cap\'{i}tulo \ref{#1}}
\newrefformat{def}{la definici\'on  \ref{#1}}
% comando recta
  • 1
    Erm, what kind of answer do you expect? You are withholding every bit of necessary information...
    – campa
    Mar 24, 2023 at 15:43
  • 1
    I don't know what else to add... Mar 24, 2023 at 15:48
  • 1
    What do you expect, if I'm asking is because I don't know where is the core of the problem. Mar 24, 2023 at 15:52
  • 2
    Well, now you've at least added some code we can look at. BTW the problem is the package mathabx, which replaces a lot of symbols.
    – campa
    Mar 24, 2023 at 15:59
  • Right, thanks then. Mar 24, 2023 at 16:00

1 Answer 1


Please always consider providing a MWE. While doing this you can very often identify the cause for your problem.

Here I did this for you. I set up a document with your default preamble, added a body (\begin{document} \[ a\cap b\] \end{document}) and compiled. The problem is reproduced, so it is a working example. It remains to make it minimal. Therefore delete one package after the other, see if the problem is still there. Like this you get the following MWE:


\[a\cap b\]

Obviously the mathabx package is responsible for the redefined symbol.

How can one resolve the problem? We'll store the original definition of \cap in \oldcap, load mathabx, and restore the old \cap. You will have to do the same for \cup.


\[a\cap b\bigcup\]


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