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C00002 00002	%ershov[e89,jmc]		Remembering Andrei
C00007 00003	\smallskip\centerline{Copyright \copyright\ 1989\ by John McCarthy}
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%ershov[e89,jmc]		Remembering Andrei
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\title{REMEMBERING ANDREI PETROVICH ERSHOV}


	I first met Andrei Ershov in December 1958 in Teddington,
England at the Teddington Conference on the Mechanization
of Thought Processes.  It was his first trip abroad and also mine.
Our contact was not large, because we were pursuing quite
different subjects at the time.

	He presented his ideas on Alpha programming language.
It was an advanced language for its time with many new ideas.
Unfortunately, it could not compete on equal terms with
Algol 60, because the latter was developed as an international
standard by the Western European and American computer science
communities.  Algol 60 might have been improved if Ershov had
been able to take part in the Paris conference in January 1960.

	I met him again in 1965 when I made my first of many
visits to the Soviet Union.  My contacts and friendship with
him were a major reason why the visits were many.  He was
already in Novosibirsk and he wanted me to visit him there
after the cybernetics conference on the ship Admiral Nakhimov.
This was not easy to arrange, because at that time Novosibirsk
was still closed to foreigners.  I remember that he gave up
and came to Moscow to meet me, but then it turned out
that the Novosibirsk arrangements had at last been made,
and we went there together.

	At that time we had more common interests---techniques
for proving that computer programs met their specifications.
However, these interests were not close enough to result in
actual collaboration.

	In November and December 1968, I spent two months in
Akademgorodok as an employee of the Computation Center and
taught a course in Novosibirsk University on program verification.
There were many good students and I became acquainted with
many Soviet institutional traditions and practices.  Andrei Ershov
assisted me through all the difficulties that arose.
Unfortunately, our invitation for him to spend six months at
Stanford working in our Computer Science Department was not
allowed.

	After that we had many contacts, always brief.  I remember
his role in favorably resolving a dispute about attendance of
a refusenik invitee at the International Joint Conference on
Artificial Intelligence in Tblisi in 1975.

	I think Ershov's single greatest scientific contribution
was in the area of partial evaluation.  He contributed some of the
first work and also played an important role in getting other
people into the field---and not only in the Soviet Union.

	It is especially unfortunate that he died when he did,
because many of the things he worked for and believed in are
only now coming to fruition.
\bye
\smallskip\centerline{Copyright \copyright\ 1989\ by John McCarthy}
\smallskip\noindent{This draft of ERSHOV[E89,JMC]\ TEXed on \jmcdate\ at \theTime}
%File originated on 09-Oct-89
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