### Noam D. Elkies

This two-part article discusses a far-reaching analogy between lattice packings in Euclidean space and linear error-correcting codes. It carries the reader through a range of pure and applied areas, including number theory, finite groups, orthogonal polynomials, and signal transmissions. Part I concentrates on sphere and lattice packings, theta functions, and modular forms.

(pp. 1238)

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### Francois Treves

Analysis of the locus ${\frak I}m\,w=|x|^2$ in two complex variables uncovers a surprisingly rich theory that involves the local behavior of biholomorphisms, the Levi form, pseudoconvexity, CR manifolds, the Heisenberg group, and questions of local solvability of linear partial differential equations.

(pp. 1246)

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### Bill Casselman

How might pictures be used better in mathematical exposition? The author gives some suggestions, using material from elementary mathematics and several historical examples of importance.

(pp. 1257)

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