2009 Formula One World Championship kept on the calendar, with the organisers of both events pulling out due to financial issues. The Abu Dhabi Grand Prix made its début appearance as the last round of the season, at the Hermann Tilke-designed Yas Marina Circuit. The race, starting at sunset, was Formula One's first day-night race. The first multi-team testing session took place at Circuit de Catalunya, Barcelona in November 2008, two weeks after the end of previous season. All teams, except Toyota, took part in the testing session where some teams tested their new aerodynamics package and slick tyres. The new look cars did not
Circuit satisfiability problem finding inputs that make the circuit output 1. (The converse, that SAT is reducible to CircuitSAT, is even easier—we simply rewrite the Boolean formula as a circuit and solve that.) Circuit satisfiability problem In theoretical computer science, the circuit satisfiability problem (also known as CIRCUIT-SAT, CircuitSAT, CSAT, etc.) is the decision problem of determining whether a given Boolean circuit has an assignment of its inputs that makes the output true. CircuitSAT has been proven to be NP-complete. In fact, it is a prototypical NP-complete problem; the Cook–Levin theorem is sometimes proved on CircuitSAT instead of on SAT for Boolean expressions