\magnification=1200
\hsize=4in
\overfullrule=0pt
\input amssym
%\def\frac#1 #2 {{#1\over #2}}
\def\emph#1{{\it #1}}
\def\em{\it}
\nopagenumbers
\noindent
%
%
{\bf Laura Ciobanu and Sa\v{s}a Radomirovi\'c}
%
%
\medskip
\noindent
%
%
{\bf Restricted Walks in Regular Trees}
%
%
\vskip 5mm
\noindent
%
%
%
%
Let ${\cal T}$ be the Cayley graph of a finitely generated free
group $F$. Given two vertices in ${\cal T}$ consider all the walks
of a given length between these vertices that at a certain time must
follow a number of predetermined steps. We give formulas for the
number of such walks by expressing the problem in terms of equations
in $F$ and solving the corresponding equations.
\bye