Couplings, coupling networks and their graphs

Definitions are proposed for some interrelated concepts that should interest, and perhaps provoke, scholars of TMM and related disciplines. Many are revisions of definitions for well-established terms provided by Commission A of IFToMM. Criticisms of some TMM definitions are cited that were made as long ago as 1876. It is argued that those same criticisms could be levelled at similar definitions in use today. A reappraisal may be overdue. Other definitions are of terms that cannot be found in the literature but are identified as necessary to provide a coherent set. The approach that has led to the new proposals stems from advances reported in the literature on electrical network and systems theory and, in particular, in the use that has been made of graph theory in representing the topological aspects of networks.