Complex sentence: In the mathematical theory of directed graphs, a graph is said to be strongly connected if every vertex is reachable from every other vertex, and its strongly connected components form a partition into subgraphs that are themselves strongly connected.
Split into simpler sentences: In the mathematical theory of directed graphs, a graph is said to be strongly connected if every vertex is reachable from every other vertex. The strongly connected components of an arbitrary directed graph form a partition into subgraphs that are themselves strongly connected.