Verifying Concurrent Graph Algorithms

We show how to verify four challenging concurrent ne-grained graph-manipulating algorithms, including graph copy, a speculativelyparallel Dijkstra and spanning tree. We develop a method of reasoning for such algorithms that dynamically tracks the contributions and responsibilities of each thread operating on a graph, even in cases of arbitrary recursive thread creation. We demonstrate how to use abstract reasoning in the style of iCAP without needing to incorporate any associated support in the underlying semantic model of the logic.