This paper explores new approaches to the symmetric traveling-salesman problem in which 1-trees, which are a slight variant of spanning trees, play an essential role. A 1-tree is a tree together with an additional vertex connected to the tree by two edges. We observe that (i) a tour is precisely a 1-tree in which each vertex has degree 2, (ii) a minimum 1-tree is easy to compute, and (iii) the transformation on “intercity distances” cij → Cij + πi + πj leaves the traveling-salesman problem invariant but changes the minimum 1-tree. Operations Research, 18, 1138–1162.

Russian Mathematical Surveys, 25, 221-262

In Linguaggi nella Societ`a e nella Tecnica, pp. 189– 224. Edizioni di Comunit`a.

See also: ACM Digital Library.CACM 13 (1):15-30

Full text available for a fee. The main purpose of the research reported here is to show that a new and more powerful type of computer-assisted instruction (CAI), based on extensive application of artificial-intelligence (AI) techniques, is feasible, and to demonstrate some of its major capabilities. A set of computer programs was written and given the name SCHOLAR. Due to its complexity, only the conception and educational aspects of this system (including an actual on-line protocol) are presented in this paper. IEEE Transactions on Man-Machine Systems MMS-ll:190-202

Russian Mathematical Surveys, 25, 221-262

CACM 12:40-46.

In Meltzer, Bernard and Donald Michie (Eds.), Machine Intelligence 5. Edinburgh University Press.

In Meltzer, Bernard and Donald Michie (Eds.), Machine Intelligence 5. Edinburgh University Press.

ACM 16:189-207.