TeX source:

F C T C=F C \times\left(n-\sum_{n=1}^{n} \sum_{T M=1}^{2} \chi_{(a, b), T M, n}\right) \text { for } \mathrm{a}=1 \ldots \mathrm{A}, \mathrm{b}=1 \ldots \mathrm{B}