What is...Bass-Serre theory?

[@punditgi]

Many thanks for your fine videos! 😊

[@VisualMath]

So nice of you, thank you for the feedback! I like trees, I hope that was clear ;-)

[@HDQuote]

looking forward to seeing your video after my exam on monday :) Thank you so much for all your high quality explanations! You really are a gift to humanity

[@VisualMath]

All the best for you exam - fingers crossed! And thanks for the kind feedback - I am certainly not a gift for humanity ;-) But that does not matter since as long as you (and anyone really) enjoy the videos I am really happy!

[@asiancollegeofteachers5870]

Another amazing video. You are such a great teacher ❤❤

[@VisualMath]

And I thank you so much for your kind words, as always ;-) I am glad that you liked the video!

[@francoisgatine4106]

Great stuff as always ! Thanks a lot !

[@VisualMath]

Thanks for the feedback: you are very welcome, as always ;-)

[@mrl9418]

In view of the fact that the fundamental group of the quotient of the real line by said action of the infinite dihedral group isn't the infinite dihedral group, I decree mathematics illegal.

[@VisualMath]

The natural reaction ;-)