I have 2 types of variables, type A (circles) and type B (squares). They are completely different from each other. However, when an instance of A occurs, an instance of B is sure to occur (or vice versa).
These instances are collected by a device (collector) with two different interfaces, A and B. The following figure describes an example (at a given time) of this scenario.
Here, several instances of type A and type B variables are present. The black circles are present at time T1 as a result of the presence of black squares at time T1. However, there are other instances that are present that are of no interest, and we can assume that they are not related at all. (e.g.: the 2 blue squares are not related to the blue circle). Similarly, 2 black circles should be seen at time T2 if 2 black squares are observed at T2.
My question: What is the best technique to find that the black squares and the black circles are related?