L is a subclass of NL, which is the class of languages decidable in logarithmic space on a nondeterministic Turing machine. A problem in NL may be transformed into a problem of reachability in a directed graph representing states and state transitions of the nondeterministic machine, and the logarithmic space bound implies that this graph has a polynomial number of vertices and edges, from which it follows that NL is contained in the complexity class P of problems solvable in deterministic polynomial time. Thus L ⊆ NL ⊆ P. The inclusion of L into P can also be proved more directly: a decider using "O"(log "n") space cannot use more than 2"O"(log "n") = "n""O"(1) time, because this is the total number of possible configurations.