2 problems

An $r$-signotope is a mapping from the $r$-subsets of an $n$-element set to $\\{+,-\\}$ satisfying the relevant monotonicity condition, and a flip changes the sign of a single $r$-…

Let an $r$-signotope be a signotope of rank $r$, and call it 2-extendable if every pair of prescribed crossing points can be contained in an extending element of an extension to an…