text: abstract
  this paper shows the complementary roles of mathematical and engineering points
  of view when dealing with truss analysis problems involving systems of linear equations and inequalities. after the compatibility condition and the mathematical structure of the general solution of a system of linear equations is discussed, the truss
  analysis problem is used to illustrate its mathematical and engineering multiple
  aspects, including an analysis of the compatibility conditions and a physical interpretation of the general solution, and the generators of the resulting affine space.
  next, the compatibility and the mathematical structure of the general solution of
  linear systems of inequalities are analyzed and the truss analysis problem revisited
  adding some inequality constraints, and discussing how they affect the resulting
  general solution and many other aspects of it. finally, some conclusions are drawn.
  key words: compatibility, cones, dual cones, linear spaces, polytopes,
  simultaneous solutions, truss analysis.
  pacs: d24, l60, 047