با استفاده از دستور \everymath
مانند نمونه زیر:
{\everymath{\displaystyle}
\begin{equation}
\label{BCC1}
\begin{array}{lll}
\min & \theta & {} \\
s.t. & \sum\limits_{j=1}^{n}{{{\lambda }_{j}}{{x}_{ij}}}\le {\theta}{{x}_{io}} & i=1,\ldots ,m \\
{} & \sum\limits_{j=1}^{n}{{{\lambda }_{j}}{{y}_{rj}}}\ge {{y}_{ro}} & r=1,\ldots ,s \\
{} & \sum\limits_{j=1}^{n}{{{\lambda }_{j}}}=1 & {} \\
{} & {{\lambda }_{j}}\ge 0 & j=1,\ldots,n \\
\end{array}
\end{equation}
}
