The aim of this books is twofold: the first is to provide a formal mathematical description of problems arising in the practical realization of switching circuits; the second is the identification of basic, necessary formal conditions for the avoidance of obvious known problems in the realization of practical switching circuits. This book contains 14 chapters, beginning with the definition of Boolean functions and examples. Next, the author covers the Hamming distance and Lipschitz functions. Morphisms are covered next, followed by anti-morphisms. The author then discusses invariant sets and invariant subsets, followed by coverage of path connected sets. Proper operation is then introduced, followed by the generalized technical condition of proper operation. The strong generalized technical condition of proper operation is then examined. Next, time-reversal symmetry is covered, followed by time-reversal symmetry vs. TCPO. Finally, the book concludes with a chapter on time-reversal symmetry vs. the generalized TCPO. Definitions and examples are provided in each chapter.