Computers have long used permutations in ordering/sorting routines. Now permutations are using computers. The connection is change ringing. The mark ordering algorithm techniques of the 1960s, used to generate permutations for computer usage, are similar to an early method of change ringing known as Plain Bob. Now computers are instrumental in solving a 350 year-old problem concerned with generating all possible permutations on a set of seven bells subject to certain restraints. This paper describes various methods of generating permutations in change ringing, gives algebraic formulations for some of them and ends with a discussion of the centuries old problem mentioned above.
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