提问于：
浏览数：
6721
MWE
```tex
\documentclass{ctexart}
\usepackage{amsmath}
\begin{document}
$\sum$
\end{document}
```
警告如下
```
Size substitutions with differences (Font) up to 0.41063pt have occurred.
LaTeX[1,1]
Font shapeOMX/cmex/m/n' in size <10> not available (Font) size<10>substituted.
LaTeX[51,1]
```
加入
```tex
\usepackage{newtxmath}
```
可以消除警告，但是我需要重定义两个数学符号
```tex
\DeclareSymbolFont{CMlargesymbols}{OMX}{cmex}{m}{n}
\let\sumop\relax\let\prodop\relax
\DeclareMathSymbol{\sumop}{\mathop}{CMlargesymbols}{"50}
\DeclareMathSymbol{\prodop}{\mathop}{CMlargesymbols}{"51}
```
这样又会有警告，如何消除？
