The intersection product for classes of rational equivalence between cycles on an Algebraic Variety.
References
Chow, W.-L. ``On Equivalence Classes of Cycles in an Algebraic Variety.'' Ann. Math. 64, 450-479, 1956.
Wilson, W. S.; Chern, S. S.; Abhyankar, S. S.; Lang, S.; and Igusa, J.-I. ``Wei-Liang Chow.'' Not. Amer. Math. Soc. 43,
1117-1124, 1996.