Equation Icon  −1 1- abc 1- a1⋅⋅⋅a6 -1 a|b1⋅⋅⋅b8 T˙T = 3!𝒟 𝒜abc(t)E + 6!𝒟 𝒜a1⋅⋅⋅a6(t)E + 9!𝒟 𝒜a |b1⋅⋅⋅b8(t)E + ⋅⋅⋅ , (9.125 )