§ 13. The Product of the Field-vectors fF.
Finally let us enquire about the laws which lead to the determination of the vector w as a function of x, y, z, t. In these investigations, the expressions which are obtained by the multiplication of two alternating matrices
are of much importance. Let us write.
Let L now denote the symmetrical combination of the indices 1, 2, 3, 4, given by
Then we shall have
In order to express in a real form, we write