Wikipedia:WikiProject Mathematics/PlanetMath Exchange/18-XX Category theory; homological algebra
This page provides a list of all articles available at PlanetMath in the following topic:
- 18-XX Category theory; homological algebra.
This list will be periodically updated. Each entry in the list has three fields:
- PM : The first field is the link to the PlanetMath article, along with the article's object ID.
- WP : The second field is either a "guessed" link to a correspondingly named Wikipedia article, produced by the script which generated the list, or one or more manually entered links to the corresponding Wikipedia articles on the subject.
- Status : The third field is the status field, which explains the current status of the entry. The recommended status entries are:
Status | means PM article |
N | not needed |
A | adequately covered |
C | copied |
M | merged |
NC | needs copying |
NM | needs merging |
- Please update the WP and Status fields as appropriate.
- if the WP field is correct please remove the qualifier "guess".
- If the corresponding Wikipedia article exists, but the link to it is wrong, please fix the link.
- If you copy or merge an article from PlanetMath, please update the WP and Status fields for that entry.
- If you have any comments, for example, thoughts on how the PlanetMath article compares to the corresponding Wikipedia article(s), please place such comments on a new indented line following the entry. Comments of this kind are very valuable.
Don't forget to include the relevant template if you copy over text or feel like an external link is warranted
- {{planetmath|id=|title=}} for copied over text
- {{planetmath reference|id=|title=}} for an external link
See the main page for examples and usage criteria.
One can use the web-based program Pmform to convert PlanetMath articles to the Wikipedia format. As a side benefit, this tool will place the PlanetMath template for you.
18-00 General reference works (handbooks, dictionaries, bibliographies, etc.)
edit- PM: category of sets, id=1895 -- WP: category of sets -- Status: A
- PM: Grothendieck spectral sequence, id=1095 -- WP: Grothendieck spectral sequence -- Status: C
- PM: monic, id=1896 -- WP: monomorphism -- Status: A
- PM: natural equivalence, id=1893 -- WP: natural equivalence -- Status: A
- PM: representable functor, id=1092 -- WP: representable functor -- Status: NM
- Just the "tensor product" example might be worth adding. — Blotwell 05:31, 3 September 2005 (UTC)
- PM: supplemental axioms for an Abelian category, id=1094 -- WP: Abelian category -- Status: NM
- Can't find these at all on WP, suggest that they belong in the Abelian category article. — Blotwell 05:31, 3 September 2005 (UTC)
- PM: diagonal functor, id=8818new! -- WP guess: diagonal functor -- Status:
- PM: equivalent definition of a representable functor, id=7788new! -- WP guess: equivalent definition of a representable functor -- Status:
- PM: identity functor, id=8817new! -- WP guess: identity functor -- Status:
- PM: monomorphisms of category of sets, id=8927new! -- WP guess: monomorphisms of category of sets -- Status:
18-01 Instructional exposition (textbooks, tutorial papers, etc.)
edit- PM: category theory, id=5622 -- WP: category theory -- Status: A
- PM: bibliography of category theory, id=8874new! -- WP guess: bibliography of category theory -- Status:
- PM: index of category theory, id=8873new! -- WP guess: index of category theory -- Status:
18A05 Definitions, generalizations
edit- PM: autofunctor, id=3560 -- WP: autofunctor -- Status: N
- Is this really notable? Google turns up only PlanetMath and some incomprehensible nonmathematical weirdness. — Blotwell 05:31, 3 September 2005 (UTC)
- PM: automorphism, id=4529 -- WP: automorphism -- Status: A
- PM: category, id=965 -- WP: category (mathematics) -- Status: A
- PM: category associated to a partial order, id=5618 -- WP: partially ordered set -- Status: NM
- This is already explained vaguely in partially ordered set but the section could be improved. — Blotwell 05:31, 3 September 2005 (UTC)
- PM: category example (arrow category), id=2983 -- WP: functor category -- Status: NM
- Should be an example in functor category, but it deserves its own redirect from arrow category too. — Blotwell 05:31, 3 September 2005 (UTC)
- PM: category isomorphism, id=5852 -- WP: isomorphism of categories -- Status: A
- PM: commutative diagram, id=3962 -- WP: commutative diagram -- Status: A
- PM: diagonal embedding, id=5817 -- WP: diagonal embedding -- Status: NC
- PM: dual category, id=2689 -- WP: dual category -- Status: A
- PM: duality principle, id=2688 -- WP: categorical duality -- Status: NC
- PM: endofunctor, id=2609 -- WP: functor -- Status: NM
- Just a one-line definition, it should be included in the functor article and endofunctor should redirect there. — Blotwell 05:31, 3 September 2005 (UTC)
- PM: epi, id=6507 -- WP: epimorphism -- Status: A
- PM: examples of initial objects and terminal objects and zero objects, id=3132 -- WP: initial object -- Status: A
- PM: forgetful functor, id=2910 -- WP: forgetful functor -- Status: A
- PM: natural transformation, id=1570 -- WP: natural transformation -- Status: A
- PM: subcategory, id=5850 -- WP: subcategory -- Status: NM
- PM: zero object, id=2864 -- WP: zero object -- Status: A
- PM: algebra formed from a category, id=8686new! -- WP guess: algebra formed from a category -- Status:
- PM: alternative definition of category, id=8845new! -- WP guess: alternative definition of category -- Status:
- PM: category of matrices, id=8712new! -- WP guess: category of matrices -- Status:
- PM: concrete category, id=8118new! -- WP guess: concrete category -- Status:
- PM: discrete category, id=8357new! -- WP guess: discrete category -- Status:
- PM: endomorphism, id=7462new! -- WP guess: endomorphism -- Status:
- PM: extremal monomorphism, id=8116new! -- WP guess: extremal monomorphism -- Status:
- PM: initial source, id=8110new! -- WP guess: initial source -- Status:
- PM: isomorphism-closed subcategory, id=8112new! -- WP guess: isomorphism-closed subcategory -- Status:
- PM: monoid as a category, id=8111new! -- WP guess: monoid as a category -- Status:
- PM: multifunctor, id=8819new! -- WP guess: multifunctor -- Status:
- PM: product of categories, id=8816new! -- WP guess: product of categories -- Status:
- PM: properties of monomorphisms and epimorphisms, id=8115new! -- WP guess: properties of monomorphisms and epimorphisms -- Status:
- PM: properties of regular and extremal monomorphisms, id=8117new! -- WP guess: properties of regular and extremal monomorphisms -- Status:
- PM: types of morphisms, id=8114new! -- WP guess: types of morphisms -- Status:
- PM: wellpowered category, id=8113new! -- WP guess: wellpowered category -- Status:
18A10 Graphs, diagram schemes, precategories
edit- PM: precategory, id=8389new! -- WP guess: precategory -- Status:
18A15 Foundations, relations to logic and deductive systems
edit- PM: well-pointed topos, id=8812new! -- WP guess: well-pointed topos -- Status:
18A20 Epimorphisms, monomorphisms, special classes of morphisms, null morphisms
edit- PM: monomorphisms are pullback stable, id=7633new! -- WP guess: monomorphisms are pullback stable -- Status:
- PM: power object, id=7630new! -- WP guess: power object -- Status:
- PM: proof that an equalizer is a monomorphism, id=7627new! -- WP guess: proof that an equalizer is a monomorphism -- Status:
18A22 Special properties of functors (faithful, full, etc.)
edit- PM: exact functor, id=1362 -- WP: exact functor -- Status: A
- PM: faithful functor, id=5849 -- WP: faithful functor -- Status: A
- PM: full functor, id=5848 -- WP: full functor -- Status: A
- PM: essentially surjective, id=7104new! -- WP guess: essentially surjective -- Status:
18A25 Functor categories, comma categories
edit- PM: Yoneda embedding, id=1638 -- WP: Yoneda lemma -- Status: A
- PM: comma category, id=8347new! -- WP guess: comma category -- Status:
18A30 Limits and colimits (products, sums, directed limits, pushouts, fiber products, equalizers, kernels, ends and coends, etc.)
edit- PM: categorical direct product, id=2855 -- WP: product (category theory) -- Status: A
- PM: categorical direct product is an inverse limit, id=5620 -- WP: product (category theory) -- Status: A
- PM: categorical direct sum, id=2859 -- WP: coproduct -- Status: A
- PM: categorical pullback, id=5579 -- WP: categorical pullback -- Status: A
- PM: direct limit, id=5619 -- WP: limit (category theory) -- Status: A
- PM: kernel is an inverse limit, id=5621 -- WP: kernel (category theory) -- Status: A
- PM: attaching pullback squares, id=9461new! -- WP guess: attaching pullback squares -- Status:
- PM: direct limit of sets, id=9127new! -- WP guess: direct limit of sets -- Status:
- PM: limiting cone, id=8355new! -- WP guess: limiting cone -- Status:
18A35 Categories admitting limits (complete categories), functors preserving limits, completions
edit- PM: complete category, id=8373new! -- WP guess: complete category -- Status:
18A40 Adjoint functors (universal constructions, reflective subcategories, Kan extensions, etc.)
edit- PM: adjoint functor, id=2691 -- WP: adjoint functor -- Status: A
- PM: equivalence of categories, id=4067 -- WP: equivalence of categories -- Status: A
- PM: reflective subcategory, id=9524new! -- WP guess: reflective subcategory -- Status:
- PM: unit of adjunction, id=9806new! -- WP guess: unit of adjunction -- Status:
- PM: universal mapping property, id=7566new! -- WP guess: universal mapping property -- Status:
18A99 Miscellaneous
edit18Axx General theory of categories and functors
edit18B25 Topoi
edit- PM: natural numbers object, id=8806new! -- WP guess: natural numbers object -- Status:
- PM: subobject classifier, id=8805new! -- WP guess: subobject classifier -- Status:
18B30 Categories of topological spaces and continuous mappings
edit- PM: category of pointed topological spaces, id=5315 -- WP: pointed space -- Status: NM
18B35 Preorders, orders and lattices (viewed as categories)
edit- PM: preorder as a category, id=8971new! -- WP guess: preorder as a category -- Status:
18B40 Groupoids, semigroupoids, semigroups, groups (viewed as categories)
edit- PM: groupoid (category theoretic), id=3575 -- WP: groupoid -- Status: A
- PM: topological groupoid, id=6149 -- WP: topological groupoid -- Status: NC
- PM: category of paths on a graph, id=8992new! -- WP guess: category of paths on a graph -- Status:
18Bxx Special categories
edit18C15 Triples (= standard construction, monad or triad), algebras for a triple, homology and derived functors for triples
edit- PM: monad, id=2614 -- WP: monad (category theory) -- Status: A
18Cxx Categories and theories
edit18D10 Monoidal categories (= multiplicative categories), symmetric monoidal categories, braided categories
edit- PM: monoidal category, id=8681new! -- WP guess: monoidal category -- Status:
18D15 Closed categories (closed monoidal and Cartesian closed categories, etc.)
edit- PM: Cartesian closed category, id=8802new! -- WP guess: Cartesian closed category -- Status:
- PM: exponential object, id=8801new! -- WP guess: exponential object -- Status:
18D35 Structured objects in a category (group objects, etc.)
edit- PM: group object, id=5606 -- WP: group object -- Status: NM
18Dxx Categories with structure
edit18E05 Preadditive, additive categories
edit- PM: additive category, id=7922new! -- WP guess: additive category -- Status:
- PM: preadditive category, id=7913new! -- WP guess: preadditive category -- Status:
18E10 Exact categories, abelian categories
edit- PM: abelian category, id=2865 -- WP: abelian category -- Status: A
- PM: enough projectives, id=6506 -- WP: enough projectives -- Status: C
- PM: exact sequence, id=2872 -- WP : exact sequence -- Status: A
- PM: projective object, id=6437 -- WP: projective object -- Status: C
- PM: examples of abelian categories, id=8931new! -- WP guess: examples of abelian categories -- Status:
- PM: proof that abelian groups form an abelian category, id=8932new! -- WP guess: proof that abelian groups form an abelian category -- Status:
18E25 Derived functors and satellites
edit18E30 Derived categories, triangulated categories
edit- PM: derived category, id=4016 -- WP: derived category -- Status: NM
18E99 Miscellaneous
edit- PM: enough injectives, id=4605 -- WP: injective object -- Status: NM
18Exx Abelian categories
edit18F10 Grothendieck topologies
edit18F20 Presheaves and sheaves
edit- PM: ringed space, id=8426new! -- WP guess: ringed space -- Status:
18F25 Algebraic $K$-theory and $L$-theory
edit18F30 Grothendieck groups
edit18Fxx Categories and geometry
edit18G05 Projectives and injectives
edit18G10 Resolutions; derived functors
edit- PM: derived functor, id=4017 -- WP: derived functor -- Status: A
- PM: delta functor, id=7317new! -- WP guess: delta functor -- Status:
- PM: horseshoe lemma, id=7799new! -- WP guess: horseshoe lemma -- Status:
18G15 Ext and Tor, generalizations, Künneth formula
edit- PM: Ext, id=4588 -- WP: Ext functor -- Status: NM
- PM: Tor, id=6090 -- WP: Tor functor -- Status: A
18G20 Homological dimension
edit18G30 Simplicial sets, simplicial objects (in a category)
edit- PM: nerve, id=3453 -- WP: nerve of a category -- Status: NC
- We already have nerve of an open covering—I'm sure this is related somehow. Anyway, merits a link from nerve (disambiguation). — Blotwell 05:31, 3 September 2005 (UTC)
- PM: simplicial category, id=3367 -- WP: simplicial category -- Status: NM
- PM: simplicial object, id=3368 -- WP: simplicial object -- Status: NC
18G35 Chain complexes
edit- PM: 5-lemma, id=4598 -- WP: Five lemma -- Status: A
- PM: 9-lemma, id=4597 -- WP: Nine lemma -- Status: A
- PM: chain homotopy, id=1572 -- WP: chain complex -- Status: NM
- PM: chain homotopy equivalence, id=6525 -- WP: chain complex -- Status: NM
- PM: chain map, id=1571 -- WP: chain complex -- Status: NM
- Chain complex needs a whole section about chain maps consisting of the content from the above three articles. Redirects from chain map and chain homotopy would be good too. — Blotwell 05:31, 3 September 2005 (UTC)
- PM: homology (chain complex), id=3721 -- WP: homology (mathematics) -- Status: A
- PM: proof of 5-lemma, id=6568 -- WP: Five lemma -- Status: A
- PM: snake lemma, id=3745 -- WP: snake lemma -- Status: A
- PM: proof of snake lemma, id=5578 -- WP: snake lemma -- Status: A
- PM: proof of 9-lemma, id=8930new! -- WP guess: proof of 9-lemma -- Status:
18G40 Spectral sequences, hypercohomology
edit- PM: Leray spectral sequence, id=1099 -- WP: Leray-Serre spectral sequence -- Status: NC
- Also redirect from Leray spectral sequence. — Blotwell 05:31, 3 September 2005 (UTC)
- PM: spectral sequence, id=4637 -- WP: spectral sequence -- Status: NM
18G60 Other (co)homology theories
edit- PM: acyclic sheaf, id=6332 -- WP: acyclic -- Status: NM
- PM: Cech cohomology group, id=6346 -- WP: Čech cohomology -- Status: A
- PM: De Rham-Weil theorem, id=6333 -- WP: De Rham-Weil theorem -- Status: C
- PM: Leray's theorem, id=6328 -- WP: Leray's theorem -- Status: C
- PM: proof of Leray's Theorem (via spectral sequences), id=6329 -- WP: Leray's theorem -- Status: N
- It's a not-especially-short proof. — Blotwell 05:31, 3 September 2005 (UTC)
- PM: Resolution of a Sheaf, id=6334 -- WP: Injective resolution -- Status: NM