👉 In computational complexity theory, an "operationally defined" (OPD) problem is a specific type of computational problem that can be solved efficiently using a computationally inexpensive operation. This operation is often referred to as "the cost function," and it is typically used in the context of optimization problems.
An OPD problem has the following characteristics:
1.
Cost Function
: The cost function for an OPD problem is defined by some linear objective function that depends on both the input variables and the output