Before proving the general result, we consider the class of system of spheres-based multiple contractions introduced in [17] and [5] and show that this class neither subsumes nor is subsumed by the class of transitively relational partial meet multiple contractions.
Furthermore, we propose two system of spheres-based constructions of multiple contractions which generate (only) transitively relational partial meet multiple contractions. Therefore we can conclude that, although it is impossible to obtain a system of spheres-based definition of all the transitively relational partial meet multiple contractions, there are classes of system of spheres-based multiple contractions which are subsumed by the class of transitively relational partial meet multiple contractions.