Equation Icon  ′ aT ⋅ Q(ξ,ξ ′) ⋅ M (ξ′)−1 ⋅ Q (ξ,ξ′)T ⋅ a 𝒞n(a,ξ,ξ ) := ------------T---------------------. (104 ) a ⋅ M (ξ ) ⋅ a