A number of important results in combinatorics, discrete geometry, and
theoretical computer science have been proved using algebraic topology.
While the results are quite famous, their proofs are not so widely
understood. This book is the first textbook treatment of a significant
part of these results. It focuses on so-called equivariant methods,
based on the Borsuk-Ulam theorem and its generalizations. The
topological tools are intentionally kept on a very elementary level. No
prior knowledge of algebraic topology is assumed, only a background in
undergraduate mathematics, and the required topological notions and
results are gradually explained.