Tired of strange British comedy videos and musical numbers which just get stranger and stranger? Wishing for some serious mathematics on this Web of ours? Well, consider your wishes fulfilled:
Be forewarned — Dr. Cheng goes fast, and she mislabels one arrow in the associativity square ([tex]T \mu[/tex] instead of [tex]\mu T[/tex]) before catching herself.
Via The n-Category Café.
Cool.
Is that a space ship landing and taking off outside?
She mislabeled the associativity square arrow! I would NEVER do something as silly as that… because I haven’t got a clue what an “associativity square” is in the first place, and so tend to avoid drawing arrows anywhere near them.