Online Appendix with an Additional Example for Subjective Auxiliary State for Coarse-Grained Concurrency

To illustrate separate verification of a library and its client, we adapt another classic example due to Owicki and Gries. The library is a one-place buffer with blocking put and get operations. The client is a pair of producer and consumer each with a private array of data that they concurrently communicate through the buffer. The producer iterates over its array, putting the elements into the buffer, one by one. The consumer populates its private array in order by getting from the buffer. The goal is to verify that at the end, the producer and consumer arrays have identical contents.