Even if we cannot limit the classes involved in the operations of some class, say A, to just one, designing A, so its operations involve few other classes usually leads to a better design than if many classes were involved.

A software engineer can state properties of their model in Alloy or TLA+ and have Alloy or TLA+ exhaustively search for counter-examples up to a given size of model.

The carrier set of an algebra is closed under the operations of the algebra.

In an algebra operations relate two disjoint carrier sets, i.e. they take elements from one set  say A, and generate elements in a different set, say B.

An algebra consists of a carrier set and operations.

Alloy allows a software engineer to explore whether/where their understanding of domain concepts might be incomplete or incorrect.

Is the sequence diagram compatible with the statechart. That is, can the sequence of events on the sequence diagram arise as (part of) a trace of the state chart.

With Alloy or TLA+ a  software engineer can automatically generate source code for the modelled Alloy concepts.

Model checking as used in Alloy or TLA+ can verify that an algorithm is correct for all possible inputs.