Sometimes the distinction between an artillery gun and a howitzer becomes blurred due to the development of gun-howitzers that can perform both roles. The best-known Allied gun-howitzer used during World War II was the British 25-Pounder Gun, which had a caliber of 87 mm.

Fantasize about sex instead of obsessing and compulsing.

One can ask if for any algebra the considered problem is always in P or NP-complete (P or coNP-complete)? For example, the problem of the satisfiability of a system of polynomial equations over a group G is in P if G is abelian and NP-complete otherwise ([7, 13]). One of the most widely known subclasses of NP which exhibits such a dichotomy, is the class of constraint satisfaction problems (CSP) on the set {0,1}, see [16]. Recently Bulatov proved the dichotomy for CSP on a three-element set [3].

Who knows? Maybe someday he'll finish writing his book and make lots of money selling it.