3 problems
Consistency conjecture. It is consistent with ZF plus the Axiom of Dependent Choices (DC) that BPI holds and there is no Vitali set in the real line.
In ZF, let a cardinal number be defined as an equivalence class under equinumerosity. For a graph, its chromatic index is the least cardinal number of colours in a proper edge-colo…
Let be a model of set theory satisfying the Axiom of Choice, and let be a permutation model inside . Suppose that Frucht's Theorem fails in . An inter…