The theorem of van Kampen

[@notgoodatmathmmm6185]

thank you! this helped me a lot :)

[@BFHThePunisher3000]

Great video! AT 6:46 you write intersection of A and B, but mean the sets A,B, right?

[@utrechtgeometrycentre9128]

You are absolutely right, thanks for spotting this!

[@jerrymahajan]

this video is such a sexy rendition of the theorem.

[@DouglasSilva-bv2om]

Impressive