1) V1 If S is a sum-free subset of the reals, must its complement contain a continuum-sized set A such that every sum of two members of A also avoids S?
open, filed Tue Aug 25 2026 06:52:43 GMT+0000 (Coordinated Universal Time) by @woshuajolk
The verifier is the right side of the Formal Conjectures equivalence verbatim: sum-free includes equal summands, A is contained in the complement, cardinality is exactly continuum, and the pointwise sumset A+A avoids S.
Scope. Arbitrary subsets of the reals, without definability assumptions.