Hi Travis,
Yes I just updated to 9.1 and have found this problem fixed, thanks.
I'd love to contribute to sage, and indeed have ideas for Verma modules
that I'd like to see if it's possible to get to work. I've not
contributed to an open source project like this before, so I imagine
I'll need to take it step by step.
Best,
Linden
On 22/09/2020 00:22, 'Travis Scrimshaw' via sage-devel wrote:
Hi Linden,
This works for me in 9.1. So this was either fixed in a later
version or possibly wasn't considered supported in version 8.9
(although probably the former). So I would recommend upgrading to the
latest version of Sage.
Side note: if you would like to contribute to Sage, the (semi)simple
Lie algebras should probably just return themselves as the derived
subalgebra.
Best,
Travis
On Tuesday, September 22, 2020 at 7:36:58 AM UTC+10, Linden Disney wrote:
On the doc page for Lie subalgebras
(https://doc.sagemath.org/html/en/reference/algebras/sage/algebras/lie_algebras/subalgebra.html
<https://doc.sagemath.org/html/en/reference/algebras/sage/algebras/lie_algebras/subalgebra.html>)
there is an example getting a subalgebra of sl3:
sl3 = LieAlgebra(QQ, cartan_type=['A',2])
D = sl3.derived_subalgebra()
This throws the error
TypeError: unsupported operand parent(s) for <: 'Coroot lattice of
the Root system of type ['A', 2]' and 'Root lattice of the Root
system of type ['A', 2]'
The error persists when calculating general subalgebras (e.g.
trying sl3.subalgebra(list(sl3.e())) ) and seems to be related to
the classical Lie algebra, as I can get subalgebras working fine
with, for example, the Heisenberg algebra (see first example on
the doc page).
I am running SageMath version 8.9, Release Date: 2019-09-29 with
system details:
Operating System: Ubuntu 18.04.4 LTS
Kernel: Linux 5.4.0-42-generic
Architecture: x86-64
--
You received this message because you are subscribed to a topic in the
Google Groups "sage-devel" group.
To unsubscribe from this topic, visit
https://groups.google.com/d/topic/sage-devel/LMFRiG9Y0ZM/unsubscribe.
To unsubscribe from this group and all its topics, send an email to
[email protected]
<mailto:[email protected]>.
To view this discussion on the web visit
https://groups.google.com/d/msgid/sage-devel/bafad702-64c1-4cab-a0f9-33bb8cc99350o%40googlegroups.com
<https://groups.google.com/d/msgid/sage-devel/bafad702-64c1-4cab-a0f9-33bb8cc99350o%40googlegroups.com?utm_medium=email&utm_source=footer>.
--
You received this message because you are subscribed to the Google Groups
"sage-devel" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/sage-devel/cb3ecfee-90ca-324a-edfe-9bc5566893be%40gmail.com.
