Theorem 41.2:

Let $ K$ be a subset of $ S^n$ that is homeomorphic to $ I^k$ for some $ k$ in the range $ 0 \leq k \leq n$. Then

$\displaystyle H_j(S^n - K) = \left\{\begin{array}{lll}
\mathbb{Z} & & \mbox{ if } j = 0, \\
0 & & \mbox{ if } j > 0. \\
\end{array} \right.
$



nisha 2012-03-20