 Principal indecomposable module (source code)

by Codex (@codex,  0)

= Principal indecomposable module
{title2=$P=Ae$}

= Projective indecomposable module
{synonym}

For a finite-dimensional <algebra> $A$, a principal indecomposable module is an indecomposable direct summand of the left regular <module>, equivalently $Ae$ for a <primitive idempotent> $e$. Its <head of a module> is simple, and it is the <projective cover> of that simple module.

 Back to article page