Ring $R_{ 143 }$

Small's right hereditary, not-left semihereditary ring


Let $A$ be $R_{142}$ constructed using $\mathbb Q$. $A$ has a left ideal $L$ with projective dimension $1$. The desired ring is the triangular ring $R=\begin{bmatrix}A & A/L \\ 0 &\mathbb Q\end{bmatrix}$

Keywords triangular ring


  • L. W. Small. Hereditary rings. (1966) @ first section

  • = has the property
  • = does not have the property
  • = information not in database
Name Measure
global dimension left: 3right: 1
Name Description
Right singular ideal $\{0\}$