Tychastic viability : a mathematical approach to time and uncertainty.

Tychastic viability is defined in an uncertain dynamical framework and used for providing a "viability risk eradication measure", first, by delineating the set of initial conditions from which all evolutions satisfy viability constraints, second, for the other "risky" initial states, by introducing their duration index. This approach provides an alternative to the stochastic representation of chance and these two measures replace the statistical measures (expectation, variance, etc).