2 problems

Let $N$ be a matroid, let $H$ be a skew hyperfield, and let $cr:CR_N\rightarrow H$ be a map assigning cross-ratio values. The map is called consistent if it arises from quasi-Plück…

The paper studies matroids over skew hyperfields and the equivalence between their circuit axioms, quasi-Plücker axioms, and dual signatures. Extension conjecture. There is no real…