% for yTeX
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\def\psetheader{
\centerline{MASSACHUSETTS INSTITUTE OF TECHNOLOGY}
\centerline{Department of Electrical Engineering and Computer Science}
\centerline{6.001 Structure and Interpretation of Computer Programs}
\centerline{Fall Semester, 1988}}

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\rectoleftheader={6.001 -- Fall Semester 1988}
\rectorightheader={Problem Set 4 -- Solutions}
\onheaders
\onfooters

\null
\vskip 1truein

\psetheader

\vskip .25truein

\centerline{Problem Set 4 -- Solutions}


\end