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2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry book bundles calculus categorical categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology colimits combinatorics complex complex-geometry computable-mathematics computer-science constructive cosmology deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry digraphs duality elliptic-cohomology enriched fibration foundation foundations functional-analysis functor gauge-theory gebra geometric-quantization geometry graph graphs gravity grothendieck group group-theory harmonic-analysis higher higher-algebra higher-category-theory higher-differential-geometry higher-geometry higher-lie-theory higher-topos-theory homological homological-algebra homotopy homotopy-theory homotopy-type-theory index-theory integration integration-theory k-theory lie-theory limits linear linear-algebra locale localization logic mathematics measure-theory modal modal-logic model model-category-theory monad monads monoidal monoidal-category-theory morphism motives motivic-cohomology nforum nlab noncommutative noncommutative-geometry number-theory of operads operator operator-algebra order-theory pages pasting philosophy physics pro-object probability probability-theory quantization quantum quantum-field quantum-field-theory quantum-mechanics quantum-physics quantum-theory question representation representation-theory riemannian-geometry scheme schemes set set-theory sheaf sheaves simplicial space spin-geometry stable-homotopy-theory stack string string-theory superalgebra supergeometry svg symplectic-geometry synthetic-differential-geometry terminology theory topology topos topos-theory tqft type type-theory universal variational-calculus

1. • CommentRowNumber1.
   • CommentAuthorDavid_Corfield
   • CommentTimeMar 26th 2021
   • PermaLink
   Author: David_Corfield
   Format: MarkdownItexFor a link. <a href="https://ncatlab.org/nlab/revision/John+Cartmell/1">v1</a>, <a href="https://ncatlab.org/nlab/show/John+Cartmell">current</a>

   For a link.

   v1, current

2. • CommentRowNumber2.
   • CommentAuthorDavid_Corfield
   • CommentTimeJun 12th 2021
   • (edited Jun 12th 2021)
   • PermaLink
   Author: David_Corfield
   Format: MarkdownItexAdded * [Entity Modelling website](http://www.entitymodelling.org/home/overview.html) Interestingly, he seems to get the point of [Hegel on the Absolute](http://www.entitymodelling.org/perspective/theabsolute.html), that a map to the unit type provides no bits of information. Perhaps $[0, X] \cong [Y, 1]$. <a href="https://ncatlab.org/nlab/revision/diff/John+Cartmell/2">diff</a>, <a href="https://ncatlab.org/nlab/revision/John+Cartmell/2">v2</a>, <a href="https://ncatlab.org/nlab/show/John+Cartmell">current</a>

   Added

   • Entity Modelling website

   Interestingly, he seems to get the point of Hegel on the Absolute, that a map to the unit type provides no bits of information. Perhaps $[0, X] \cong [Y, 1]$.

   diff, v2, current

3. • CommentRowNumber3.
   • CommentAuthorUrs
   • CommentTimeJun 13th 2021
   • (edited Jun 13th 2021)
   • PermaLink
   Author: Urs
   Format: MarkdownItexCompare "[[empty context]]" for the [[unit type]] when regarded as a [[context]]. I've tried to look around a little on that Entity Modelling website, but I don't have a clear picture yet what it's doing.

   Compare “empty context” for the unit type when regarded as a context.

   I’ve tried to look around a little on that Entity Modelling website, but I don’t have a clear picture yet what it’s doing.

4. • CommentRowNumber4.
   • CommentAuthorDavid_Corfield
   • CommentTimeJun 13th 2021
   • PermaLink
   Author: David_Corfield
   Format: MarkdownItexIt seems Cartmell went off into industry after academic work on contextual categories that's become relevant for HoTT practitioners. This entity modelling seems to be about representing an everyday conceptualisation of the world.

   It seems Cartmell went off into industry after academic work on contextual categories that’s become relevant for HoTT practitioners. This entity modelling seems to be about representing an everyday conceptualisation of the world.

5. • CommentRowNumber5.
   • CommentAuthorUrs
   • CommentTimeJul 20th 2022
   • PermaLink
   Author: Urs
   Format: MarkdownItexadded pointer to * [[John Cartmell]], *Generalised Algebraic Theories and Contextual Categories*, PhD thesis, Oxford University (1978) &lbrack;[pdf](https://ncatlab.org/nlab/files/Cartmell-Thesis.pdf)&rbrack; (however, I had to compress this pdf so much make it fit into the server's file size constraint that now the quality is rather bad) <a href="https://ncatlab.org/nlab/revision/diff/John+Cartmell/3">diff</a>, <a href="https://ncatlab.org/nlab/revision/John+Cartmell/3">v3</a>, <a href="https://ncatlab.org/nlab/show/John+Cartmell">current</a>

   added pointer to

   • John Cartmell, Generalised Algebraic Theories and Contextual Categories, PhD thesis, Oxford University (1978) [pdf]

   (however, I had to compress this pdf so much make it fit into the server’s file size constraint that now the quality is rather bad)

   diff, v3, current

6. • CommentRowNumber6.
   • CommentAuthorjonsterling
   • CommentTimeJul 21st 2022
   • PermaLink
   Author: jonsterling
   Format: MarkdownItexInterestingly, I believe that for John, the entity modeling stuff is really part of a continuous/long-term line of interest that was present in his work on GATs.

   Interestingly, I believe that for John, the entity modeling stuff is really part of a continuous/long-term line of interest that was present in his work on GATs.