For my question, let us consider the following scenario.
We have a quasi-variety generated by a finite algebra (i.e. ). Now, let be another finite algebra in . Assume that there exists an integer such that, for each , every homomorphism is essentially at most -ary.
My question is: Is it guaranteed that there exists a finite algebra with such that, for each , every homomorphism is essentially at most unary?
To illustrate this question, I will now give an example in which this is true. Let and be two finite distributive lattices. Now, there exists an integer such that the essential artiy of every is at most -ary. We can define to be the (up to isomorphism unique) two-element distributive lattice.
Note that is not required (although it is true in the example). It is only required to have .
Is this always possible? I believe it is not, but I do not know any counterexample up to this point in time. Does anybody know a counterexample, a proof or has a feeling of whether this statement is true or false?
Note: If the answer to my question would be positive, this would have some very nice consequences for centralizer clones (which is my main research interest at the time). In fact, this would mean (and I can explain later, why that is) that every centralizer clones that has bounded essential arity cannot contain many types of functions. Among them: Near-unanimity operations, minority operations, semiprojections etc.. Furthermore, it would lead to a full characterization of all minimal clones in centralizer clones with bounded essential arity.
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