 A familiar example of a computational problem is that of primality testing – i.e. that of deciding \(n \in \sc{PRIMES} \)?  This problem was intensely studied in mathematics long before the development of digital computers.  (See, e.g., (Williams 1998) for a history of primality testing and  (Crandall and Pomerance 2005) for a recent survey of the state of the art.)   After a number of preliminary results in the 19th and 20th centuries, the problem \(\sc{PRIMES}\) was shown in 2004 to possess a so-called polynomial time decision algorithm – i.e. the so-called AKS primality test (Agrawal, Kayal, and Saxena 2004). This qualifies \(\sc{PRIMES}\) as feasibly decidable relative to the standards which are now widely accepted in complexity theory and algorithmic analysis (see   Section 2.2).