  We present the algorithmic procedure determining the impulsive behavior of a
rigid disk having a single or possibly multiple frictionless impact with two
walls forming a corner. The algorithmic procedure represents an application of
the general theory of multiple impacts as presented in
\cite{Pasquero2016Multiple} for the ideal case.
  In the first part, two theoretical algorithms are presented for the cases of
ideal impact and Newtonian frictionless impact with global dissipation index.
The termination analysis of the algorithms differentiates the two cases: in the
ideal case, we show that the algorithm always terminates and the disk exits
from the corner after a finite number of steps independently of the initial
impact velocity of the disk and the angle formed by the walls; in the
non--ideal case, although is not proved that the disk exits from the corner in
a finite number of steps, we show that its velocity decreases to zero and the
termination of the algorithm can be fixed through an "almost at rest"
condition.
  In the second part, we present a numerical version of both the theoretical
algorithms that is more robust than the theoretical ones with respect to noisy
initial data and floating point arithmetic computation. Moreover, we list and
analyze the outputs of the numerical algorithm in several cases.
