I have written a notation representing a counter for a condition:
$M \leftarrow \displaystyle \sum_{i =1}^{|X|} [B_j = X_i]$
So far this gives me a number for a specific j (the counter), but I want to turn this into a set for all values of j in such a way M is representing a multiset. M would be something like this:
$M = \{1,1,2,4,5\}$
How can I fix my notation to represent what I want?
thanks