  This work revisits the constant stepsize stochastic approximation algorithm
for tracking a slowly moving target and obtains a bound for the tracking error
that is valid for the entire time axis, using the Alekseev non-linear variation
of constants formula. It is the first non-asymptptic bound for the entire time
axis in the sense that it is not based on the vanishing stepsize limit and
associated limit theorems unlike prior works, and captures clearly the
dependence on problem parameters and the dimension.
