APPENDIX A: Notation and Mathematical Conventions In this appendix we collect our notation, and some related mathematical facts and conventions.

A.1

SET NOTATION AND CONVENTIONS If X is a set and x is an element of X, we write x 2 X. A set can be specified in the form X = {x | x satisfies P }, as the set of all elements satisfying property P . The union of two sets X1 and X2 is denoted by X1 [ X2 , and their intersection by X1 \ X2 . The empty set is denoted by Ø. The symbol 8 means “for all.” The set of real numbers (also referred to as scalars) is denoted by