Have you ever seen homomorphisms act so strangely?

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See, that’s what the app is perfect for.

Sounds perfect Wahhhh, I don’t wanna
isomorphismes
isomorphismes

“In dimensions ≥5, topology and algebra match up simply. In dimensions 3 and 4, manifolds are more interesting. We used to wonder if there was some key idea from high-dimensional manifolds that would extend at least down to dimension 4, making 4-manifolds easy to understand. There is such a principle: Imbedding 2-handles in smooth 4-dimensional manifolds-with-boundary subject to a homotopy criterion. This high-dimensional idea does work in 4 dimensions and give us insight into 4-manifolds.”

the topology of 4-manifolds by michael hartley freedman

(heavily reworded by me)

Source: projecteuclid.org