However, this reduction is more liberal than the standard reduction used in computational complexity (sometimes called polynomial-time many-one reduction); for example, the complexity of the characteristic functions of an NP-complete problem and its co-NP-complete complement is exactly the same even though the underlying decision problems may not be considered equivalent in some typical models of computation.
Year 2000 problem | Waring's problem | The Final Problem | Decision at Sundown | Aakhari Decision | The Problem with Popplers | Record of Decision | NATO Double-Track Decision | Hume and the Problem of Causation | Dirichlet problem | Boolean satisfiability problem | The Dog Problem | Tammes problem | Species problem | problem solving | Problem gambling | Packing problem | packing problem | Executive Decision | decision-making | decision | chess problem | Znám's problem | Your Decision | Year 10,000 problem | Yamabe problem | Weber problem | Undecidable problem | Travelling salesman problem | travelling salesman problem |
In 1997 Russell Impagliazzo and Avi Wigderson proved that the construction of Nisan and Wigderson is a pseudorandom generator assuming that there exists a decision problem that can be computed in time 2O(n) on inputs of length n but requires circuits of size 2Ω(n).
Emil Post, "Formal Reductions of the General Combinatorial Decision Problem," American Journal of Mathematics 65 (2): 197-215, 1943.