Formula_21846

\[\begin{gathered}e_{i} \wedge e_{j}=-e_{j} \wedge e_{i} ;, j=1, \ldots, n, e_{i} \wedge e_{i}=0, \\1 \wedge e_{i}=e_{i} \wedge 1=e_{i}, i=1, \ldots, n, 1 \wedge 1=1 .\end{gathered}\]