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C00002 00002	\\M1BASL30\M2BASB30\M3NGR25\M4NGR20\F2\CSTANFORD UNIVERSITY
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\\M1BASL30;\M2BASB30;\M3NGR25;\M4NGR20;\F2\CSTANFORD UNIVERSITY
\F3\CSTANFORD, CALIFORNIA 94305
\F4COMPUTER SCIENCE DEPARTMENT\←L\-R\/'7;\+R\→.\→S   Telephone:
\←S\→.415-321-2300
\F1\CMarch 18,1974



Dr. John Backus
IBM Research Laboratory
San Jose, Calif

Dear Dr. Backus:

\JI just finished indoctrinating Bill McKeeman's class at Santa Cruz
in the glories of LISP. In conversation with Monib Khademi I learned a bit
about your RED languages. It seems like your meta composition is closely
related to an old LISP trick called macros. In calling a LISP macro
what is passed is the whole call on the macro. The body of the macro
can then perform arbitrary computations.

I am enclosing a couple of pages of my notes on LISP which describes
the behavior of macros.

I would be interested in learning  more about RED languages even though
I am an inveterate LISP hacker.
\.
\←L\→S\←R\-L\/'2;\+L\→L

Yours sincerely,



John R. Allen
Research Associate
Computer Science Dept
Artificial Intelligence Labs

\←S\→L
JRA:pdp10