Hi All,
I'm using SageMath 9.1 on Windows Native.
When affine_connection has no content and I display it, I get a ValueError that stops the computation.
M = Manifold(3, 'M', start_index=1)
c_xyz.<x,y,z> = M.chart()
nab = M.affine_connection('nabla', r'\nabla')
print(nab)
nab.display()
IMO it should display something like 'Empty' or 'Null' or '{}' but not an error.
Daniel
