Equation Icon  a ℓ = 0 : K b, ℓ = 1 : Eabc = E [abc], ℓ = 2 : Ea1⋅⋅⋅a6 = E[a1⋅⋅⋅a6], (9.102 ) ℓ = 3 : Ea |b1⋅⋅⋅b8 = Ea |[b1⋅⋅⋅b8],