WEBAutomated Planning: Introduction and Overview 9 State-Transition Systems as Graphs A state-transition system Σ = (S,A,E,γ) can be represented by a directed labelled graph G = (N G,E G) where: • the nodes correspond to the states in S, i.e. N G =S; and • there is an arc from s∈N G to s%∈N G, i.e. s→s %∈E