Hypergraph rewriting and Causal structure of $\lambda -$calculus

In this paper, we first study hypergraph rewriting in categorical terms in an attempt to define the notion of events and develop foundations of causality in graph rewriting. We introduce novel concepts within the framework of double-pushout rewriting in adhesive categories. Secondly, we will study the notion of events in $\lambda -$calculus, wherein we construct an algorithm to determine causal relations between events following the evaluation of a $\lambda -$expression satisfying certain conditions. Lastly, we attempt to extend this definition to arbitrary $\lambda -$expressions.