OY The NX:

5[Rockefellen& THE ROCKEFELLER UNIVERSITY
a University JE 1230 YORK AVENUE. NEW YORK, NY 10021
“> a March 19, 1981

JOSHUA LEDERBERG

PRESIDENT

Professor Charles A. R. Hoare
Oxford University

45 Banbury Road

Oxford OX2 6PE

England

Dear Professor Hoare:

I was very much interested to read your 1980 Turing
Lecture in the CACM recently. If you have a letterpress
reprint to spare I would be grateful for it.

The main reason I am writing is to ask you to elabo-
rate a bit further about your anxieties concerning ADA.
You used as a horror story the failure of a "Space rocket
to Venus". Perhaps your allusion was to the 1962 soft-
ware failure of a Ranger mission to the moon; but I would
be happy to be corrected further about the specific inci-
dent.

More important I have been trying to find a further
postmortem on that incident that would help me to relate
the anomaly to the question of langudge design. It would
be difficult for me to go further without first tapping ~
your own insight into the circumstance and into the design
issue.

You are raising a principle that must be taken with
the utmost seriousness and I simply ask you to provide me
with the concrete detail that might help me follow it up.

Yours sincerely,

Shua Lederberg

A.C. MAE

Cael. On Q Chronology