I heard this example was given in Whitehead's paper A CERTAIN OPEN MANIFOLD WHOSE GROUP IS UNITY.( http://qjmath.oxfordjournals.org/content/os-6/1/268.full.pdf ) But I was shocked by his terms. I'm sure I have to read something before looking at it. So what's your suggestions? Probably because of my ignorant, I'm also wondering did his term remain standard today? But since my aim is to know about an example of this kind, any alternative will do either. ps, do I need to explain in detail where I got lost? I don't prefer doing that because I got lost everywhere, for eg. feeling uncertain about his "circuit", "element", "solid", and "symbol",....