sage: m = matrix(ZZ, 0, 0)
sage: m.permutation_normal_form()
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
Cell In[8], line 1
----> 1 m.permutation_normal_form()
File ~/micromamba/envs/flatsurf/lib/python3.10/site-packages/sage/matrix/matrix2.pyx:8442, in sage.matrix.matrix2.Matrix.permutation_normal_form (build/cythonized/sage/matrix/matrix2.c:58991)()
8440 for i in range(nrows)]
8441 # and find the maximal one:
-> 8442 first_row = max(sorted_rows)
8443 first_rows = [j for j in range(nrows) if sorted_rows[j] == first_row]
8444 # We construct an array S, which will record the subsymmetries of the
ValueError: max() arg is an empty sequence