TCS Journal 2025 Journal Article
Expressive completeness of separation logic in block-based cloud storage systems
- Tianyue Cao
- Zhao Jin
- Bowen Zhang
- Yongzhi Cao
- Hanpin Wang
Block-based cloud storage systems are widely used to store big data. Although they are highly fault-tolerant, the occurrence of bugs is still inevitable. Separation logic was proposed for mutable data structures, and can be used to verify block-based cloud storage systems. Hoare-style proof system has been constructed to verify these systems, and has been implemented in Coq. However, expressiveness of the assertion language in this formal system has not been fully studied. To fill this gap, we show the expressive completeness of separation logic in block-based cloud storage system, and prove the following three main consequences: (1) this logic is strictly more expressive than first-order logic, (2) this logic is as expressive as separation logic, and (3) this logic is as expressive as weak second-order logic with sequences.