2019/03/16 by Chan, William, Jackson, Stephen
#FOS: Mathematics #Logic (math.LO)
paper · doi:10.48550/arxiv.1903.07005
ZF + AD proves that for all nontrivial forcings ℙ on a wellorderable set of cardinality less than Θ, 1ℙ \Vdashℙ \negAD. ZF + AD + Θ is regular proves that for all nontrivial forcing ℙ which is a surjective image of ℝ, 1ℙ \Vdashℙ \negAD. In particular, ZF + AD + V = L(ℝ) proves that for every nontrivial forcing ℙ ∈ LΘ(ℝ), 1ℙ \Vdashℙ \negAD.