# In $n>5$, topology = algebra

During the study of the surgery theory I faced following sentence:

Surgery theory works best for $n > 5$, when
topology = algebra“.

I don’t know what is the meaning of topology=algebra. Can someone clear the sentence to me?

In the interest of recording the answers in the comments above and removing the question from the “unanswered” queue, I note the following.

Henry Horton:

There is a completely algebraic theory of surgery developed by Ranicki. See the following notes (especially section 5): http://www.maths.ed.ac.uk/~aar/surgery/ranicki.pdf

PseudoNeo:

This is quite beautifully explained in the first chapter of Scorpan’s nice The Wild World of 4-Manifolds. I recommend it strongly.