Persistent Invariant :
assertions which must hold at any post-crash state of the program.
— SMT-Based Verification of Persistency Invariants of Px86 Programs
A global property that is also the research topic of many other works, e.g. POG
似乎有另一种定义的方式：
“The current practice requires the programmers to specify and enforce PM related program invariants. These invariants must identify not only the objects that should be made persistent but also the order in which they should be made persistent.” (Huang et al., 2024, p. 1795)