Update cheatsheet.fr.md

12.temporary_ins/08.conservative-vector-fields/20.conservative-vector-fields-properties/20.overview/cheatsheet.fr.md

@@ -404,7 +404,7 @@ $`\color{brown}{\large{\mathbf{d\phi=\overrightarrow{grad}\,\phi_M\cdot\overrigh
 $`\;=\big(X_{\alpha}\;\overrightarrow{e_{\alpha}}+X_{\beta}\;\overrightarrow{e_{\beta}}+X_{\gamma}\;\overrightarrow{e_{\gamma}}\big)
 \cdot\big(dl_{\alpha}\;\overrightarrow{e_{\alpha}}+dl_{\beta}\;\overrightarrow{e_{\beta}}+dl_{\gamma}\;\overrightarrow{e_{\gamma}}\big)`$
 
-$`\begin{align}{l}
+$`\begin{align}
 \; &= X_{\alpha}\,dl_{\alpha}\,\big(\overrightarrow{e_{\alpha}}\cdot\overrightarrow{e_{\alpha}}\big)
 +X_{\alpha}\,dl_{\beta}\,\big(\overrightarrow{e_{\alpha}}\cdot\overrightarrow{e_{\beta}}\big)
 +X_{\alpha}\,dl_{\gamma}\,\big(\overrightarrow{e_{\alpha}}\cdot\overrightarrow{e_{\gamma}}\big)\\