# How to import few symbols like \int and \sum from mtpro2?

In a similar question it is possible to adopt Greek characters in math mode from mtrpo2 to be used together with newtxmath and baskervaldx.

My question is similar, except, I would like to adopt some other symbols like \int, \sum, or even brackets \left\{ and \right\}.

Instead of completely switching to mtpro2, I like to use newtxmath as the main math font for the consistency with baskervaldx text font, since the text font can be natively used in math.

Is it possible to import the above symbols form mtpro2 or even from the default computer modern font?

Here are the differences, using newtxmath:

and using mtpro2:

\documentclass[10pt]{article}

\usepackage{amsmath}

% Option 1, using newtxmath

% Option 2, using mtpro2 (I only need a few symbols from this package
% \usepackage{etex}
% \usepackage[lite]{mtpro2}

\begin{document}
\begin{equation*}
L^2_0(\Omega) = \left\{ f \in L^2(\Omega)  ~:~ \int_{\Omega} f dx = 0 \right\}.
\end{equation*}
\end{document}



Please try with this:

\documentclass[10pt]{article}

\usepackage{amsmath}

% Option 1, using newtxmath

% Option 2, using mtpro2 (I only need a few symbols from this package
% \usepackage{etex}
% \usepackage[lite]{mtpro2}

\DeclareFontFamily{U}{mtt}{}
\DeclareFontShape{U}{mtt}{m}{up}{<->mt2exa}{}

\DeclareSymbolFont{splgreek}{U}{mtt}{m}{up}
\SetSymbolFont{splgreek}{normal}{U}{mtt}{m}{up}

\DeclareMathSymbol{\splsum}{\mathop}{splgreek}{"50}
\let\sum\splsum
\DeclareMathSymbol{\intop}{\mathop}{splgreek}{"52}

\begin{document}
\begin{equation*}
\sum    L^2_0(\Omega) = \left\{ f \in L^2(\Omega)  ~:~ \int_{\Omega} f dx = 0 \right\}.
\end{equation*}
\end{document}


Output:

• I appreciate your response, it works perfectly. May I ask to explain above solution? How do you find the codes for each symbol, like "50 for int? For example if I want to do the same for say \prod and the brackets \left\{ and \right\} where should I look at? – Sia Oct 21 at 20:45