dual | Year 2000 problem | Dual | Waring's problem | The Final Problem | The Problem with Popplers | Hume and the Problem of Causation | Dual SIM | Dirichlet problem | Boolean satisfiability problem | The Dog Problem | Tammes problem | Super Dual Auroral Radar Network | Species problem | problem solving | Problem gambling | Packing problem | packing problem | Dual! Parallel Trouble Adventure | Dual number | Dual education system | chess problem | Znám's problem | Year 10,000 problem | Yamabe problem | Women's Dual Moguls World Champion | Weber problem | Undecidable problem | Travelling salesman problem | travelling salesman problem |
Perturbation function, mathematical function which relates the primal and dual problems.