%%  Abstract for: A primer on Galois connections
%%  with Marcel Ern/'e, Austin Melton and George E. Strecker

  We provide the rudiments of the theory of Galois connections (or
  residuation theory, as it is sometimes called) together with many
  examples and applications.  Galois connections occur in profusion
  and are well-known to most mathematicians who deal with order
  theory; they seem to be less known to topologists.  However, because
  of their ubiquity and simplicity, they (like equivalence relations)
  can be used as an effective research tool throughout mathematics and
  related areas.  If one recognizes that a Galois connection is
  involved in a phenomenon that may be relatively complex, then many
  aspects of that phenomenon immediately become clear; and thus, the
  whole situation typically becomes much easier to understand.