# What is a hyper property?

I am reading the paper Foundations and tools for the static analysis of Ethereum contracts, by Grischenko et al. Sometimes the authors speak about hyper properties (e.g. Section 5). What exactly is a hyper property in this context?

A property is a set of traces. E.g. all those traces where variable $x$ is never negative.
A hyperproperty is a set of sets of traces. E.g. the sets of traces $T$ where each trace in $T$ is finite.