Research on heuristic functions is all about estimating the length (or cost) of solution paths. But what if there is no such path? Many known heuristics have the ability to detect (some) unsolvable states, but that ability has always been treated as a by-product. No attempt has been made to design heuristics specifically for that purpose, where there is no need to preserve distances. As a case ...

A natural way to benefit from distribution is via asynchronous invocations to methods or services. Upon invocation, a request is enqueued at the destination side and the caller can continue its execution. But a question remains: “what if one wants to manipulate the result of an asynchronous invocation?” First-class futures provide a transparent and easy-to-program answer: a future acts as the p...

We would like to arrive at a single coherent pair of credences in X and X. Perhaps we wish to use these to set our own credences; or perhaps we wish to publish them in a report of the WHO as the collective view of expert epidemiologists; or perhaps we wish to use them in a decision-making process to determine how medical research funding should be allocated in 2018. Given their expertise, we wo...

An injective map from the vertex set of a graph G—its order may not be finite—to the set of all natural numbers is called an arithmetic (a geometric) labeling of G if the map from the edge set which assigns to each edge the sum (product) of the numbers assigned to its ends by the former map, is injective and the range of the latter map forms an arithmetic (a geometric) progression. A graph is c...

Compounds of indicative conditionals present some puzzling phenomena. Perhaps most striking, some nested indicative conditionals are uninterpretable. Proponents of NTV hold that indicative conditionals do not have truth values, and they use this to explain why nested indicative conditionals are sometimes uninterpretable: the embedded conditional does not provide the truth conditions needed by t...