~~to find out the ~~multiplicity of elements in a ~~given matrix from a list containing a set of matrices~~list

if one has a list ~~containing a set ~~of matrices how ~~one can write a code which will give output as ~~do we build a dictionary ~~where the ~~whose keys are the distinct matrices in the list and values are the number of times that matrix appears in the list ~~or ~~(or the multiplicity of that matrix in the ~~list.~~list).