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∂AIL Prof. Andrei P. Ershov↓Computation Center↓Novosibirsk 630090↓USSR∞

Dear Andrei:

	The final volume of the encyclopedia arrived today.  It has been
almost eleven years since the subscription started, and I would never
have let you take so much trouble had I supposed they would come one
at a time over such a long period.  Anyway thanks very much for all
your trouble.  I have found the encyclopedia very informative and have
found numerous occasions for comparing its treatment of a subject with
that of the Encyclopedia Britannica.  I must say that in general the
Britannica is better, but I have often found facts in the Soviet
Encyclopedia that were not in the Britannica.

	Is there any American book I can send you or bring you?

	I will be at IBM in Yorktown Heights between July 15 and
September 1 in their visiting professor program.

	Under separate cover I am sending you a copy of a new approach
to proving the properties of sequential programs called Elephant.

.reg