A survey of minimal clones

SummaryA clone is a set of composition closed functions on some set. A non-trivial fact is that on a finite set every clone contains a minimal clone. This naturally leads to the problem of classifying all minimal clones on a finite set. In this paper I survey what is known about this classification. Rather than repeat the arguments used in the original papers, I have tried to use known results about finite algebras to give a more coherent and unified description of the known minimal clones.