  Brouwer's fixed point theorem from 1911 is a basic result in topology - with
a wealth of combinatorial and geometric consequences. In these lecture notes we
present some of them, related to the game of HEX and to the piercing of
multiple intervals. We also sketch stronger theorems, due to Oliver and others,
and explain their applications to the fascinating (and still not fully solved)
evasiveness problem.

Combinatorics;Algebraic Topology