  Given a fractional differential equation of order $\alpha \in (0,1]$ with
Caputo derivatives, we investigate in a quantitative sense how the associated
solutions depend on their respective initial conditions. Specifically, we look
at two solutions $x_1$ and $x_2$, say, of the same differential equation, both
of which are assumed to be defined on a common interval $[0,T]$, and provide
upper and lower bounds for the difference $x_1(t) - x_2(t)$ for all $t \in
[0,T]$ that are stronger than the bounds previously described in the
literature.
