Level rings and algebras with straightening laws
Let R be a graded Cohen-Macaulay k-algebra with Hilbert series \((h_ 0+h_ 1t+...+h_ st^ s)/(1-t)^ d\), \(h_ s\neq 0\). Then R is called level if \(h_ s=CM\)-type(R). The main part of this article consists in proving the following theorem: Every graded 3-dimensional domain with straightening law is level.
graded 3-dimensional domain with straightening law
scientific article; zbMATH DE number 4063236