Equation 10.2.1005E65A6873F9

\begin{equation} \gamma _1\wedge \cdots \wedge \gamma _{n-1}-\gamma '_1\wedge \cdots \wedge \gamma '_{n-1}=\sum _{m=1}^{n-1}\gamma _1\wedge \cdots \wedge \gamma _{m-1}\wedge (\gamma _ m-\gamma '_ m)\wedge \gamma '_{m+1}\wedge \cdots \wedge \gamma '_{n-1}. \end{equation}