Excision in algebraic obstruction theory

In this paper the relative algebraic obstruction groups (also known as Euler class groups) were defined and some excision exact sequences were established. In particular, for a regular domain AA, essentially of finite type over an infinite field kk, and a rank one projective AA-module L0L0, it was proved that En(A[T],L0⊗A[T])≈En(A,L0)whenever 2n≥dimA+4.