Changes between Initial Version and Version 25 of Ticket #16340


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Timestamp:
Aug 16, 2014, 8:12:40 AM (8 years ago)
Author:
Nicolas M. Thiéry
Comment:

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  • Ticket #16340

    • Property Status changed from new to needs_review
    • Property Work issues changed from to find good names
    • Property Summary changed from Model full subcategories to Infrastructure for modelling full subcategories
    • Property Branch changed from to public/categories/full_subcategories-16340
    • Property Milestone changed from sage-6.3 to sage-6.4
    • Property Commit changed from to 737a8f0c80a80040cb3c0308b1d2063f456662d0
  • Ticket #16340 – Description

    initial v25  
    9797     Category of unital magmas: "1"}
    9898}}}
     99== Limitation ==
     100
     101The current model forces the following assumption: `C\subset B\subset
     102A` is a chain of categories and `C` is a full subcategory of `A`, then
     103`C` is a full subcategory of `B` and `B` is a full subcategory of `A`.
     104In particular, we can't model situations where, within the context of
     105`C`, any `A` morphism is in fact a `B` morphism because the `B`
     106structure is rigid.
     107
     108Example: C=Groups, B=Monoids, A=Semigroups.
     109
     110This is documented in details in the methods .is_fullsubcategory and
     111.full_super_categories.
    99112
    100113== Questions ==
     
    102115- Find good names for all the methods above
    103116
    104 - How to handle the case where the extra structure is forced by the
    105   context, and automatically preserved by morphisms? E.g. the trivial
    106   Euclidean structure on fields?
     117- Ideas on how to later lift the limitation?