# summation on an index and a set

I have an index `DC` and a set of values `CM`, and `it is a CM element` and `CM` is a subset of `DC`. I have two summations shown above. The first sum is complete index `DC` and the subset `CM`. The light brown part of the first sum says that the sum should only include if `c` is an element of `CM`. The second point is about the elements of `CM`.

These two summations appear in an equation (not given here for the sake of simplicity). Is there an easy way to make these summations?

Thank you…