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1. • CommentRowNumber1.
   • CommentAuthorUrs
   • CommentTimeJan 6th 2020
   • PermaLink
   Author: Urs
   Format: MarkdownItexstarting something -- not done yet, but need to save <a href="https://ncatlab.org/nlab/revision/%27t+Hooft+double+line+notation/1">v1</a>, <a href="https://ncatlab.org/nlab/show/%27t+Hooft+double+line+notation">current</a>

   starting something – not done yet, but need to save

   v1, current

2. • CommentRowNumber2.
   • CommentAuthorUrs
   • CommentTimeJan 6th 2020
   • (edited Jan 6th 2020)
   • PermaLink
   Author: Urs
   Format: MarkdownItexnow some substance in place, including various graphics. **Question:** Did anybody else notice/make explicit in print that Bar-Natan's discussion of marked surfaces in relation to Lie algebra weight systems (section 6 in [Bar-Natan 95](https://ncatlab.org/nlab/show/'t+Hooft+double+line+notation#BarNatan95)) is exactly the 't Hooft double line construction for $\mathfrak{so}(N)$? <a href="https://ncatlab.org/nlab/revision/%27t+Hooft+double+line+notation/1">v1</a>, <a href="https://ncatlab.org/nlab/show/%27t+Hooft+double+line+notation">current</a>

   now some substance in place, including various graphics.

   Question: Did anybody else notice/make explicit in print that Bar-Natan’s discussion of marked surfaces in relation to Lie algebra weight systems (section 6 in Bar-Natan 95) is exactly the ’t Hooft double line construction for $\mathfrak{so}(N)$?

   v1, current

3. • CommentRowNumber3.
   • CommentAuthorUrs
   • CommentTimeJan 7th 2020
   • PermaLink
   Author: Urs
   Format: MarkdownItexadded another early reference on the case of $SO(N)$ and $Sp(N)$: * G.M. Cicuta, _Topological Expansion for $SO(N)$ and $Sp(2n)$ Gauge Theories_, Lett. Nuovo Cim. 35 (1982) 87 ([spire:177713](http://inspirehep.net/record/177713), [doi:10.1007/BF02754653](https://doi.org/10.1007/BF02754653)) <a href="https://ncatlab.org/nlab/revision/diff/%27t+Hooft+double+line+notation/4">diff</a>, <a href="https://ncatlab.org/nlab/revision/%27t+Hooft+double+line+notation/4">v4</a>, <a href="https://ncatlab.org/nlab/show/%27t+Hooft+double+line+notation">current</a>

   added another early reference on the case of $SO(N)$ and $Sp(N)$:

   • G.M. Cicuta, Topological Expansion for $SO(N)$ and $Sp(2n)$ Gauge Theories, Lett. Nuovo Cim. 35 (1982) 87 (spire:177713, doi:10.1007/BF02754653)

   diff, v4, current

4. • CommentRowNumber4.
   • CommentAuthorUrs
   • CommentTimeJan 8th 2020
   • PermaLink
   Author: Urs
   Format: MarkdownItexadded a graphics with an actual example before passing to surfaces ([here](https://ncatlab.org/nlab/show/'t+Hooft+double+line+notation#Example)) <a href="https://ncatlab.org/nlab/revision/diff/%27t+Hooft+double+line+notation/12">diff</a>, <a href="https://ncatlab.org/nlab/revision/%27t+Hooft+double+line+notation/12">v12</a>, <a href="https://ncatlab.org/nlab/show/%27t+Hooft+double+line+notation">current</a>

   added a graphics with an actual example before passing to surfaces (here)

   diff, v12, current

5. • CommentRowNumber5.
   • CommentAuthorUrs
   • CommentTimeJan 8th 2020
   • PermaLink
   Author: Urs
   Format: MarkdownItexadded another example of the surface-valued construction ([here](https://ncatlab.org/nlab/show/'t+Hooft+double+line+notation#SurfaceExample)) <a href="https://ncatlab.org/nlab/revision/diff/%27t+Hooft+double+line+notation/13">diff</a>, <a href="https://ncatlab.org/nlab/revision/%27t+Hooft+double+line+notation/13">v13</a>, <a href="https://ncatlab.org/nlab/show/%27t+Hooft+double+line+notation">current</a>

   added another example of the surface-valued construction (here)

   diff, v13, current