title: Classification of stable configurations of plane mirrors.
abstract: We have studied the stability of systems of plane mirrors by using a new way to describe ray transformations caused by such systems. All stable systems comprising as many as three mirrors are described and classified. Besides the well-known corner cube, infinitely many stable retroreflecting and direction-preserving three-mirror systems have been found.
authors.forename: Y
authors.initials: Y
authors.lastname: Friedman
authors.forename: N
authors.initials: N
authors.lastname: Schweitzer