MAR 15 1985

United States Army
BIOLOGICAL LABORATORIES
Fort Detrick, Frederick, Maryland 21701

SMUFD-BR-C 12 March 1965

Dr. Joshua Lederberg

Department of Genetics

Stanford University School of Medicine
Palo Alto, California 94304

Dear Dr. Lederberg:

Thank you again for your keen observations on polycyclic cage-coding
problems. Long ago I reminded our notation team members (Addelston,
Bonnett, Gelberg, Granito, Smith, and--later--Bowman, Landee, Schultz,
and Sorter) that ring conventions are "defective" in finishing with an
open rather than closed box. Our Least Effort justification is that the
importance of any structural groups must be divided by two or three
million--and that's a big denominator!

That old "Rule 30" requires a much more careful elaboration than I
gave in my "frontier phraseology" of 1954. In practice, the correct
notation traces a path of least measures; like your DENDRAL, it is easier
to do than explain, and it positively does not depend on any diagrammatic
orientation! My trial analyses are shown on an attached sheet.

Dr. Elbert G. Smith has taken Sabbatical leave from Mills College to
devote his full time to a necessary elaboration and clarification of our
notation for computer users. Since he is in San Francisco (1931 Golden
Gate), I believe that it would be mutually profitable for you two to get
acquainted; you can make far more intensive exchanges of ideas than we
in the east can offer with letters.

Meanwhile, I will enjoy postal exchanges as swiftly as you care to
continue.

Sincerely,
Worn), Wirwtosin

WILLIAM J. WISWESSER
Research Chemist
Crops Division

Encl

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