text/blobdef.tex
changeset 488 efcc71e5489f
parent 487 c576b7868f05
child 489 bdbd890086eb
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487:c576b7868f05 488:efcc71e5489f
   157 \begin{example}
   157 \begin{example}
   158 Consider the four subsets of $\Real^3$,
   158 Consider the four subsets of $\Real^3$,
   159 \begin{align*}
   159 \begin{align*}
   160 A & = [0,1] \times [0,1] \times [-1,1] \\
   160 A & = [0,1] \times [0,1] \times [-1,1] \\
   161 B & = [0,1] \times [-1,0] \times [-1,1] \\
   161 B & = [0,1] \times [-1,0] \times [-1,1] \\
   162 C & = [-1,0] \times \setc{(y,z)}{z \sin(1/z) \leq y \leq 1, z \in [-1,1]} \\
   162 C & = [-1,0] \times \setc{(y,z)}{z^2 \sin(1/z) \leq y \leq 1, z \in [-1,1]} \\
   163 D & = [-1,0] \times \setc{(y,z)}{-1 \leq y \leq z \sin(1/z), z \in [-1,1]}.
   163 D & = [-1,0] \times \setc{(y,z)}{-1 \leq y \leq z^2 \sin(1/z), z \in [-1,1]}.
   164 \end{align*}
   164 \end{align*}
   165 Here $A \cup B = [0,1] \times [-1,1] \times [-1,1]$ and $C \cup D = [-1,0] \times [-1,1] \times [-1,1]$. Now, $\{A\}$ is a valid configuration of blobs in $A \cup B$, and $\{C\}$ is a valid configuration of blobs in $C \cup D$, so we must allow $\{A, C\}$ as a configuration of blobs in $[-1,1]^3$. Note however that the complement is not a manifold.
   165 Here $A \cup B = [0,1] \times [-1,1] \times [-1,1]$ and $C \cup D = [-1,0] \times [-1,1] \times [-1,1]$. Now, $\{A\}$ is a valid configuration of blobs in $A \cup B$, and $\{C\}$ is a valid configuration of blobs in $C \cup D$, so we must allow $\{A, C\}$ as a configuration of blobs in $[-1,1]^3$. Note however that the complement is not a manifold.
   166 \end{example}
   166 \end{example}
   167 
   167 
   168 \begin{defn}
   168 \begin{defn}