Irrational Tiling by Logical Quantifiers

Alvy Ray Smith

**LICS Cover
1988-2013***** **
**- 24 Years!**

©1988, Alvy Ray Smith, All Rights Reserved.

Because of the success of the FOCS
(Foundations of Computer Science) cover design, I was asked to design, in 1988, a
cover for the first proceedings of a daughter conference, the LICS (Logic in Computer Science)
symposium. At the time I was teaching myself PostScript and also reading the marvelous
text *Tilings and Patterns* by Grunbaum and Shephard who describe an
aperiodic tiling of the plane discovered by Penrose. As a tribute to the logicians who
would attend LICS, I patterned the Penrose "kite and dart" tiles, used for the
aperiodic tiling, with the universal quantifier symbol, an upside-down uppercase A. It is
well-known that the irrational numbers have aperiodic decimal expansions, so I was tickled
by the juxtaposition of the "irrational", or aperiodic tiling, with the logical
[the very epitome of rational] symbol. The cover has been used annually since then* under the same arrangement as for the FOCS design, a free copy of
the proceedings. Counting LICS 2013 then, the cover has now been in use
24 years.

Created at Pixar in Marin County, California in 1988.

*with the exception of 1989 and 2010. Not used 2014-2015.