Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

I'm reading R.E. Gompf and A.I. Stipsicz, 4-Manifolds and Kirby Calculus. I don't understand Remarks 4.4.1 on page 116-117 Google books here.

At first I can't understand why we take immersed disk $D \subset Y$ with boundary $K \subset \partial _{+}Y$.

Next, I can't understand on the counterexamples

$X \approx D^4 , X ' \approx S^2\times D^2-intD^4$ .

If you can help me, then please teach me the reason for this

share|improve this question
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.