Section: New Results

Drags

Shared and cyclic structures are very common in both programming and proving, which requires generalizing term rewriting techniques to graphs. Jean-Pierre Jouannaud and Nachum Dershowitz have introduced a very general class of multigraphs, called drags, equipped with a composition operator $\otimes$ which provides with a rich categorical structure. Rewriting a drag $D$ can then be defined in a very simple way, by writing $D$ as the composition of a left-hand side of rules $L$ and a context $C$, and then replacing $L$ by $R$, the right-hand side of the rule, which yields the rewritten drag $R\otimes C$. The fundamental aspects of the algebra of drags have been presented at TERMGRAPH'2018 and have also been submitted to a special issue of TCS. Termination of drag rewriting in investigated in [20].