Les say i have two sets od objects. Set A and set B if two sets are identical (composition wise) then there exists a bijective mapping function and the frequency of object a in set A is equal to object a' in B. That holds for all objects.
If i relax the mapping constraints and say that mapping a in A to b' in B is good enough and mapping b in A to c' in B is also ok, then i have a problem grasping on how to use frequencies in order to determine the similarity between two sets.
Does anyone have any experience or a suggestion on how to determine how much two sets are similar if only frequency can be looked at and a mapping function is relaxed as described above?
Identity: a->a' only
any articles , and ideas , any suggestions are welcomed.
thank you very much