(88) X_{_x_} + Y_{_y_} + Z_{_z_} + T_{_t_} = 0,
and according to 83), T_{_t_} > 0. In special cases, where ω vanishes it
follows from 81) that
X_{_x_}² = Y_{_y_}² = Z_{_z_}² = T_{_t_}², = (Det^{1/4} S)²,
and if T, and one of the three magnitudes X_{_x_}, Y_{_y_}, Z_{_z_} are
= ±Det^{1/4} S, the two others = -Det^{1/4} S. If Ω does not vanish let
Ω ≠ 0, then we have in particular from 80)
T_{_z_} X_{_t_} = 0, T_{_z_} Y_{_t_} = 0, Z_{_z_} T_{_z_} + T_{_z_}
T_{_t_} = 0,
and if Ω₁ = 0, Ω₂ = 0, Z_{_z_} = -T_{_t_} It follows from (81), (see
also 83) that
X_{_x_} = -Y_{_y_} = ±Det^{1/4} S,
and -Z_{_z_} = T_{_t_} = √(Det^{½} S + εμΩ₃²) > Det^{1/4}S.