Opened 4 years ago

Closed 3 years ago

#23375 closed defect (fixed)

Cannot pull back from PBW basis to Lie algebra

Reported by: tscrim Owned by:
Priority: major Milestone: sage-8.0
Component: algebra Keywords: lie algebras
Cc: sage-combinat, salisbury1 Merged in:
Authors: Travis Scrimshaw Reviewers: Frédéric Chapoton
Report Upstream: N/A Work issues:
Branch: 33cea7d (Commits) Commit: 33cea7dd974940c823e1e5ad1199742dbc1d6c30
Dependencies: #23373 Stopgaps:

Description

This should work but doesn't: 

sage: L = lie_algebras.cross_product(QQ)
sage: pbw = L.pbw_basis()
sage: L(pbw(L.an_element())) == L.an_element() # BOOM

This is due to not setting inverse_on_support when creating the coercion. This also exposes the need to overwrite term for LieAlgebraWithStructureCoefficients.

Change History (13)

comment:1 Changed 4 years ago by tscrim

  • Branch set to public/lie_algebras/fix_pbw_preimage-23375
  • Commit set to 3271f6d6ff365a0b638349ba5dd1fffb88e61768
  • Status changed from new to needs_review

New commits:

​3271f6dFixing preimage for PBW bases.

comment:2 Changed 4 years ago by chapoton

  • Reviewers set to Frédéric Chapoton
  • Status changed from needs_review to positive_review

thanks, let it be

comment:3 Changed 4 years ago by vbraun

  • Status changed from positive_review to needs_work

Merge conflict

comment:4 Changed 4 years ago by git

  • Commit changed from 3271f6d6ff365a0b638349ba5dd1fffb88e61768 to 88642772f81c684cf4f9dc961bb5c2bb75def3e9

Branch pushed to git repo; I updated commit sha1. New commits:

​750c712Fixing ordering of indices vs _basis_key.
​8864277Merge branch 'public/lie_algebras/fix_stucture_coeffs-23373' of git://trac.sagemath.org/sage into public/lie_algebras/fix_pbw_preimage-23375

comment:5 Changed 4 years ago by tscrim

  • Dependencies set to #23373
  • Status changed from needs_work to needs_review

Essentially a trivial rebase over #23373, but this should have someone else check that the tests still pass in the lie_algebras folder.

comment:6 Changed 4 years ago by tscrim

Patchbot is back to green, and I am pretty certain #23373 is the only conflict.

comment:7 Changed 4 years ago by git

  • Commit changed from 88642772f81c684cf4f9dc961bb5c2bb75def3e9 to 8baf26a8f2d20dc37f8453d4c5273d873f76ddef

Branch pushed to git repo; I updated commit sha1. New commits:

​9046b90Fixing doctest failure.
​8baf26aMerge branch 'public/lie_algebras/fix_stucture_coeffs-23373' into public/lie_algebras/fix_pbw_preimage-23375

comment:8 Changed 4 years ago by git

  • Commit changed from 8baf26a8f2d20dc37f8453d4c5273d873f76ddef to 33cea7dd974940c823e1e5ad1199742dbc1d6c30

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

​bc4dbf5Making doctest robust.
​33cea7dFixing preimage for PBW bases.

comment:9 Changed 3 years ago by tscrim

Green 8.0 patchbot; independent build failure of the 8.1beta0.

comment:10 Changed 3 years ago by tscrim

8.1beta0 bot is morally green.

comment:11 Changed 3 years ago by chapoton

  • Status changed from needs_review to positive_review

ok, good to go

comment:12 Changed 3 years ago by tscrim

Thank you again.

comment:13 Changed 3 years ago by vbraun

  • Branch changed from public/lie_algebras/fix_pbw_preimage-23375 to 33cea7dd974940c823e1e5ad1199742dbc1d6c30
  • Resolution set to fixed
  • Status changed from positive_review to closed
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