Simon Willerton - The projection formula, extranatural transformations and surface diagrams

 

Wouldn't it be nice if one day in the future you could specify the string/surface diagram representation as a morphism in CAT and have your computer generate the code to display the diagrams in your slides? That would be even cooler than HTML-in-canvas, wouldn't it?  See Laurie Wired on Richard Gabriel's 35-year-old essay "Worse Is Better"

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