描述了二级与三级三角矩阵代数的模范畴部分AR序列,给出子代数模范畴的AR序列如何扩张为相应的三角矩阵代数模范畴的AR序列.
Gives some AR-sequences of triangular matrix algebras of order two and order three,which explain how an AR-sequence over a subalgebra expands to an AR-sequence over the responding triangular matrix algebra.