  As mentioned before, P is a good mathematical wrapper for the set of feasible problems.  There are problems in P requiring \(n^{1,000}\) time for problems of size \(n\) and thus not feasible.  Nature appears to be our friend here, which is to say naturally occurring problems in P favor relatively simple algorithms, and “natural” problems tend to be feasible. The number of steps required for problems of size \(n\) tends to be less than \(c n^k\) with small multiplicative constants \(c\), and very small exponents, \(k\), i.e., \(k\leq 2\).