\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(collection-int?  \col)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return \#t if \col is a collection of \verb+int+ objects.  $O(1)$\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(size  \col )
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return the number of elements in \coln. $O(n)$\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(null?  \col )
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return \#t if \col has 0 elements. $O(1)$\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(member?  \val \col)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return \val if it is in the colleciton \coln; otherwise return \#f. $O(n)$\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(insert!  \val \col)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Add the element \val to colleciton \coln. If \col does not allow multiple 
 elements, requests for multiple insertion of an element are ignored.  Time 
 complexity depends on collection implementation.\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(remove! \val \col)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Remove the element \val to colleciton \coln. If \val occurred $k$ times
 before the call, it will occur $k-1$ times afterwards. Time complexity 
 depends on collection implementation.\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(clear!  \col)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Remove all of the elements from colleciton \coln. $O(n)$\end{minipage}
\end{minipage}
\vspace{0.2in}


\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(occurrences  \val \col)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Remove number of times element \val occurs in collection \coln. $O(n)$ \end{minipage}
\end{minipage}
\vspace{0.2in}


\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(eq?  \colone \coltwo $\ldots$ \colk)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return true if all argments are the same object. $O(n)$\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(eqv?  \colone \coltwo $\ldots$ \colk)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return true if all argments are collections with the same elements. $O(n)$\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(\lth  \colone \coltwo $\ldots$ \colk)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return true if \coli \lth \colj whenever $i \lth j$. Ordering
 is lexicographic. $O(n)$\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(\ltheq  \colone \coltwo $\ldots$ \colk)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return true if \coli \ltheq \colj whenever $i \ltheq j$. Ordering
 is lexicographic. $O(n)$\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(\gth  \colone \coltwo $\ldots$ \colk)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return true if \coli \gth \colj whenever $i \gth j$. Ordering
 is lexicographic. $O(n)$\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(\gtheq  \colone \coltwo $\ldots$ \colk)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return true if \coli \gtheq \colj whenever $i \gtheq j$. Ordering
 is lexicographic. $O(n)$\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(+  \colone \coltwo $\ldots$ \colk)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return a multiset containing the union of \colone $\ldots$ \colkn, i.e. 
 each occurrence of each element of collection \coli is added to the result.
 Time complexity depends on the types of the \colin.\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(\^  \colone \coltwo $\ldots$ \colk)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return a multiset containing the intersection of \colone $\ldots$ \colkn. The
 number of occurrences of element $i$ in the result is the minimum number
 of occurrences of $i$ in any \colin.
 Time complexity depends on the types of the \colin.\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(-  \colone \coltwo $\ldots$ \colk)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return a multiset containing the difference of \colone $\ldots$ \colkn. 
 If \rji\ denotes the number of occurrences of element $i$ in \coljn, 
 then the number of occurrences of $i$ in the result is the maximum
 of 0 and the difference between \ronei and the sum from 2 to $k$ of
 \rji.  Time complexity depends on the types of the \colin.\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(subset  \colone \coltwo $\ldots$ \colk)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return \#t if $\colone \subseteq \coltwo \subseteq \colk$.
 Time complexity depends on the types of the \colin.\end{minipage}
\end{minipage}
\vspace{0.2in}
 

\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(proper-subset  \colone \coltwo $\ldots$ \colk)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return \#t if $\colone \subset \coltwo \subset \colk,$ where 
 $\coli \subset \colj$ if and only if for each element $e$ in
 the $\coli \cup \colj$, $r\_i(e) $<$ r\_j(e)$.
 Time complexity depends on the types of the \colin.\end{minipage}
\end{minipage}
\vspace{0.2in}


\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(cartesian-product  \set1 \set2n)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return the set of all ordered pairs in the cartesian product of \set1 and
\set2n.  $O(n^2)$.\end{minipage}
\end{minipage}
\vspace{0.2in}


\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(choose  \set \kn)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return the set of all k-subsets of $\setn,$ where  $\set$ is a LINK
 $\set$ class object (not a multiset or sequence). $O(2^n)$.\end{minipage}
\end{minipage}
\vspace{0.2in}


\begin{minipage}[t]{8in}
\begin{tabular}{ll}
 & \index{Collection!}(power-set  \set)
\end{tabular}\\


 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Return the set of all subsets of $\setn,$ where  $\set$ is a LINK
 $\set$ class object (not a multiset or sequence). $O(2^n)$.\end{minipage}
\end{minipage}
\vspace{0.2in}