Grobner-Shirshov Basis for affine Weyl Group $\widetilde{A_n}$
  Using Buchberger-Shirshov Algorithm and Composition-Diamond lemma we obtain the reduced Grobner-Shirshov bases of $\widetilde{A_n}$ and classify all reduced words of the affine Weyl group $\widetilde{A_n}$. 
Erol Y{\i}lmaz, Cenap \"Ozel and U\u{g}ur Ustao\u{g}lu
math.GR