Opened 6 years ago

Last modified 5 years ago

#18263 needs_work defect

reintroduce `__neg__` for magmas cartesian product

Reported by: vdelecroix Owned by:
Priority: major Milestone: sage-6.7
Component: categories Keywords:
Cc: nthiery, cnassau Merged in:
Authors: Vincent Delecroix Reviewers:
Report Upstream: N/A Work issues:
Branch: u/vdelecroix/18263 (Commits) Commit: af11981fecdeb91b886b21962626d7ae7d720a65
Dependencies: #16836 Stopgaps:

Description (last modified by vdelecroix)

In #16836 the __neg__ operation for cartesian product was moved from AdditiveMagmas to the AdditiveMagmas.WithInverse(). The operation was ambiguous but the feature is lost. We just revert the removal.

Moreover, there was a bug in Cartesian products of CombinatorialFreeModule as this generic __neg__ was called instead of the customized _neg_ which worked (see ​#16836 comment:22 and ​#16836 comment:23)! We replace _neg_ with __neg__ in CombinatorialFreeModule.

Change History (3)

comment:1 Changed 6 years ago by vdelecroix

  • Description modified (diff)

comment:2 Changed 6 years ago by vdelecroix

  • Authors set to Vincent Delecroix
  • Branch set to u/vdelecroix/18263
  • Commit set to af11981fecdeb91b886b21962626d7ae7d720a65
  • Description modified (diff)
  • Status changed from new to needs_review

New commits:

​6e9cf9eTicket 16836 fix __neg__ for cartesian products
​af11981Trac 18263: __neg__

comment:3 Changed 5 years ago by chapoton

  • Status changed from needs_review to needs_work

needs rebase, does not apply

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