  We consider an M/G/1 queue in which the customers, while waiting in line, may
renege from it. We study the Nash equilibrium profile among customers, and show
that it is defined by two sequences of thresholds. For each customer, the
decision is based on the observed past (which determines from what sequence the
threshold is taken), and the observed queue length (which determines the
appropriate element in the chosen sequence). We construct the a of equations
that has the Nash equilibrium as its solution, and discuss the relationships
between the properties of the service time distribution and the properties of
the Nash equilibrium, such as uniqueness and finiteness.
