\begin{equation}
\underset{\hat{\beta}\in \mathbb{A}}{\min }\,\underset{\beta \in \mathbb{B}}{%
\sup }\quad R\left( \underaccent{\wtilde}{\hat{\beta}}^{\ast },%
\underaccent{\wtilde}{\beta},A\right) =\underset{\beta \in \mathbb{B}}{\sup }%
\left( \underaccent{\wtilde}{\hat{\beta}}^{\ast },\underaccent{\wtilde}{%
\beta},A\right) \Rightarrow \hat{\beta}^{\ast }\text{ is minimax}
\end{equation}
請問一下,小弟這一行語法出了什麼問題
出現了以下問題
! Undefined control sequence.
<argument> \wtilde
l.1478 ...left( \underaccent{\wtilde}{\hat{\beta}}
^{\ast },%
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.
! Undefined control sequence.
<argument> ...cc@shift \scriptscriptstyle \wtilde
$}\hidewidth
l.1478 ...left( \underaccent{\wtilde}{\hat{\beta}}
^{\ast },%
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.
! Undefined control sequence.
<argument> \wtilde
l.1478 ...left( \underaccent{\wtilde}{\hat{\beta}}
^{\ast },%
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.
! Undefined control sequence.
<argument> ...cc@shift \scriptscriptstyle \wtilde
$}\hidewidth
l.1478 ...left( \underaccent{\wtilde}{\hat{\beta}}
^{\ast },%
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.