| | SL (complexity) (Site not responding. Last check: 2007-10-29) |
 | | Although originally described in terms of symmetric Turing machines, that equivalent formulation is very complex, and the reducibility definition is what is used in practice. |
 | | USTCON is a special case of STCON (directed reachability), the problem of determining whether a directed path between two vertices in a directed graph exists, which is complete for NL. |
 | | Because USTCON is SL-complete, most advances that impact USTCON have also impacted SL. |
| www.worldhistory.com /wiki/S/SL-(complexity).htm (1243 words) |