題目：Canonical models for fragments of the Axiom of Choice.
アブストラクト：We present technology for investigation of natural forcing extensions of the model L(R) which satisfy such statements as “there is a nonprincipal ultrafilter on the integers” or “there is a total selector for the Vitali equivalence relation”. The technology reduces many questions about ZF implications between consequences of the axiom of choice to natural ZFC forcing problems.