Richard Southwell on Another Interesting Symmetric Monoidal Category

See https://graphicallinearalgebra.net/, https://homotopy.io/ and Brendan Fong and David Spivak - Seven Sketches in Compositionality: An Invitation to Applied Category Theory.

See Richard Southwell on Coxeter Groups and Discrete Mathematics from which this is a kind of follow-up. Also Daniel Tubbenhauer Explaining What Lie Groups and Lie Algebras Are. It's also an appeal to studying things by translating them into other languages: see Mark Jago on Type Theory in Computer Science, Logic and Linguistics.

See also Ian Clarke on Freenet.

The final screen: adding complex numbers

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Norman Wildberger's take on complex numbers:


... and quaternions, ...

Recovering the algebra:

Subscribe to Insights into Mathemathematics.

John Baez - The periodic Table of n-Categories.  He starts by explaining why it is that "categorification" seems ad hoc: it's because it's to undo an accidental decategorification (9:12)!



 

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