Update cheatsheet.fr.md

12.temporary_ins/07.geometry-coordinates-prop2/40.n4/20.overview/cheatsheet.fr.md

@@ -881,17 +881,6 @@ $`\large{\mathbf{v}=v^a\,\mathbf{e_a}}`$
 
 dérivée partielle covariante
 
-$`\begin{align}
-\Large{\color{blue}{\partial_b\mathbf{v}}}&=\partial_b\,(v^a\,\mathbf{e_a})\\
-\\
-&=(\partial_b\,v^a)\;\mathbf{e_a} + v^a\,(\partial_b\;\mathbf{e_a})\\
-\\
-&=(\partial_b\,v^a)\,\mathbf{e_a}+\underbrace{v^a\,\Gamma_{ab}^{\;c}\,\mathbf{e_c}}_{\color{brown}{
-\begin{array}{c}\text{a et c muets}\\ \Rightarrow \\ \text{interchangeables}\end{array}}}\\
-\\
-&\Large{\color{blue}{=\big(\partial_b\,v^a + v^a\,\Gamma_{cb}^{\;a}\big)\,\mathbf{e_a}}}
-\end{align}`$
-
 
 $`\begin{align}
 \Large{\color{blue}{\partial_b\mathbf{v}}}&=\partial_b\,(v^a\,\mathbf{e_a})\\
@@ -899,7 +888,7 @@ $`\begin{align}
 &=(\partial_b\,v^a)\;\mathbf{e_a} + v^a\,(\partial_b\;\mathbf{e_a})\\
 \\
 &=(\partial_b\,v^a)\,\mathbf{e_a}+\underbrace{v^a\,\Gamma_{ab}^{\;c}\,\mathbf{e_c}}_{\color{brown}{
-\begin{array}{c}\text{a et c muets} \Rightarrow \\ \text{interchangeables}\end{array}}}\\
+\begin{array}{c}\text{a et c muets} \,\Longrightarrow \\ \text{interchangeables}\end{array}}}\\
 \\
 &\Large{\color{blue}{=\bigg(\partial_b\,v^a + v^a\,\Gamma_{cb}^{\;a}\bigg)\,\mathbf{e_a}}}
 \end{align}`$