THE DEGREE STRUCTURE OF WEIHRAUCH REDUCIBILITY
We answer a question by VASCO BRATTKA and GUIDO GHERARDI by proving that the Weihrauch lattice is not a Brouwer algebra. The computable Weihrauch lattice is also not a Heyting algebra, but the continuous Weihrauch lattice is. We further investigate embeddings of the Medvedev degrees into the Weihrauch degrees.
heyting algebra medvedev degrees weihrauch degrees superintuitionistic logic computable analysis