The main theorem of Linear Programming Duality, relating a "pri- mal"
Linear Programming problem to its "dual" and vice versa, can be seen as
a statement about sign patterns of vectors in complemen- tary subspaces
of Rn. This observation, first made by R.T. Rockafellar in the late six-
ties, led to the introduction of certain systems of sign vectors, called
"oriented matroids". Indeed, when oriented matroids came into being in
the early seventies, one of the main issues was to study the fun-
damental principles underlying Linear Progra.mrning Duality in this
abstract setting. In the present book we tried to follow this approach,
i.e., rather than starting out from ordinary (unoriented) matroid
theory, we pre- ferred to develop oriented matroids directly as
appropriate abstrac- tions of linear subspaces. Thus, the way we
introduce oriented ma- troids makes clear that these structures are the
most general -and hence, the most simple -ones in which Linear
Programming Duality results can be stated and proved. We hope that this
helps to get a better understanding of LP-Duality for those who have
learned about it before und a good introduction for those who have not.