Das Schönste, was wir erleben können,
ist das Geheimnisvolle.
Mein Weltbild, Albert Einstein.
It is not our purpose to develop the complete theory of the symmetric group,
tableaux, or Schubert polynomials. We want in fact to touch a few aspects of the
underlying theories to introduce some notions, set up notations as well as to
establish some relations between the mathematical objects manipulated by
ACE.