56 research outputs found

    Unreachability of Inductive-Like Pointclasses in L(R)L(\mathbb{R})

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    Hjorth proved from ZF+AD+DCZF + AD + DC that there is no sequence of distinct Σ21\Sigma^1_2 sets of length δ21\delta^1_2. Sargsyan extended Hjorth's technique to show there is no sequence of distinct Σ2n1\Sigma^1_{2n} sets of length δ2n1\delta^1_{2n}. Sargsyan conjectured an analogous property is true for any regular Suslin pointclass in L(R)L(R) -- i.e. if κ\kappa is a regular Suslin cardinal in L(R)L(R), then there is no sequence of distinct κ\kappa-Suslin sets of length κ+\kappa^+ in L(R)L(R). We prove this in the case that the pointclass S(κ)S(\kappa) is inductive-like
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