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1. • CommentRowNumber1.
   • CommentAuthorDavid_Corfield
   • CommentTimeJul 8th 2010
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   Author: David_Corfield
   Format: MarkdownItexBegan [planar algebra](http://ncatlab.org/nlab/show/planar+algebra) for no very good reason.

   Began planar algebra for no very good reason.

2. • CommentRowNumber2.
   • CommentAuthorUrs
   • CommentTimeJul 8th 2010
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   Author: Urs
   Format: MarkdownItexThanks! Added a link to the SBS entries on planar algebras.

   Thanks!

   Added a link to the SBS entries on planar algebras.

3. • CommentRowNumber3.
   • CommentAuthorDavid_Corfield
   • CommentTimeJul 8th 2010
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   Author: David_Corfield
   Format: MarkdownItexI remember John saying somewhere that he couldn't quite believe the definition of a planar algebra had to be so complicated. I wonder if there's something slicker than def 2.3.1 of Jones' [Quadratic Tangles in Planar Algebras](http://uk.arxiv.org/abs/1007.1158).

   I remember John saying somewhere that he couldn’t quite believe the definition of a planar algebra had to be so complicated. I wonder if there’s something slicker than def 2.3.1 of Jones’ Quadratic Tangles in Planar Algebras.

4. • CommentRowNumber4.
   • CommentAuthorUrs
   • CommentTimeJul 8th 2010
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   Author: Urs
   Format: MarkdownItexI don't have the time to look into this now, but I seem to recall on SBS Scott Morrison and others give very natural definitions in terms of pivotal categories.

   I don’t have the time to look into this now, but I seem to recall on SBS Scott Morrison and others give very natural definitions in terms of pivotal categories.