  A method for detecting possible non-deterministic dynamics underlying a time
series is introduced. Non-deterministic dynamics may arise due to the failure
of the Lipschitz condition in the equations of motion. At a singular point, the
phase space trajectory of the system may jump from one solution to another.
This discontinous change implies divergence of the second derivative of the
solution whenever it passes near the singular point. A time series can be
examined for such divergences, which may indicate non-determinism in the
dynamical system. Examples with both simulated and actual data are given.
