Complex sentence: \\ begin E_x (t)\\\\ E_y (t)\\ end, where E_x (t) and E_y (t) are the (linearly polarized) "x" and "y" components of the electric field of the light wave.
Split into simpler sentences: \\ begin E_x (t)\\\\ E_y (t)\\ end. The variables E_x (t) and E_y (t) are the (linearly polarized) "x" and "y" components of the electric field of the light wave.