  Trying to enumerate all of the walks in a 2D lattice is a fun combinatorial
problem and there are numerous applications, from polymers to sports. Computers
provide a wonderful tool for analyzing these walks; we provide a Maple package
for automatically describing generating functions of walks restricted to any
step set in a 2D lattice. We always obtain a closed system of relations for
generating functions of walks that are bounded, semi-bounded, or unbounded. For
bounded walks, this leads to explicit rational solutions! For semi-bounded or
unbounded walks, we may get lucky and obtain algebraic solutions; if not, we
still have a short self-referential description of the generating function.
