This paper’s purpose is to present a functional description of a groupware-type application that controls the environmental management process [Michelis] [Dix 1996]. The application, named SIGMA, was developed for PETROBRAS and has three main objectives: to provide the users information on the process of environmental licensing; to help users conduct this work and allow a better interaction bet...

Alan L. Olmstead is Professor of Economics and Director of the Institute of Governmental Affairs at the University of California, Davis, 95616, and member of the Giannini Foundation of Agricultural Economics. E-mail: [email protected]. Paul W. Rhode is Professor of Economics at the University of Arizona, Tucson, 85721-0108 and Research Associate at the NBER. E-mail: [email protected].

We give a general construction of affine noetherian algebras with the property that every finite dimensional representation is completely reducible. Starting from enveloping algebras of semi simple Lie algebras in characteristic zero we obtain explicit examples and describe some of their properties. In the following an algebra A will always mean an associative algebra over a field k with a unit...

The death of R. Alan Day on November 26, 1990 was a great loss to the community of lattice theorists and universal algebraists. Alan was a hard working, hard playing man whose enthusiasm for mathematics and life will be greatly missed by all of us. This paper concentrates on congruence identities, i.e., lattice equations satisfied by the congruence lattices of all the algebras in a variety. Alt...