Let $A$ be a finite dimensional algebra and $T$ a (tilting, if that helps) module of $A$.
Question: What is the best way to test whether $T$ is (isomorphic to) a two-sided ideal of $A$ using the GAP-package QPA?
I thought about the following criterion but it is a bit slow in practise: $T$ is a two-sided ideal if and only if trace map $tr_T(A) \rightarrow A$ is injective and $tr_T(A)$ is isomorphic to $T$ as right modules. Here the trace $tr_T(A)$ is defined as the maximal submodule of $A$ that is generated by $T$. It is a two-sided ideal and can be obtained in QPA using the "TraceOfModule" command.