  Hardy's nonlocality is a "nonlocality proof without inequalities": it
exemplifies that quantum correlations can be qualitatively stronger than
classical correlations. This paper introduces variants of Hardy's nonlocality
in the CHSH scenario which are realized by the PR-box, but not by quantum
correlations. Hence this new kind of Hardy-type nonlocality is a proof without
inequalities showing that superquantum correlations can be qualitatively
stronger than quantum correlations.

Quantum Physics