  Nowadays, numerous services based on large-scale distributed systems have
been developed to boost the convenience of human life. On the other side, it
becomes a significant challenge to ensure the correctness and properties of
these systems due to the complex and nested architecture. Although concurrent
separation logic (CSL) has partially tackled the problem by specifying systems
and verifying the correctness of them, it faces modularity issues. In this
paper, we propose an extended concurrent separation logic (ECSL) to address the
modularity issues of CSL with the support of the temporal extension,
communication extension, environment extension, and nest extension. ECSL is
capable of formalizing systems at different abstraction levels from memory
management to architecture and protocol design with great modularity.
Furthermore, we stick to unitarity and compatibility principles while
developing ECSL.
