  Instead of studying evolutions governed by an evolutionary system starting at
a given initial state on a prescribed future time interval, finite or infinite,
we tackle the problem of looking both for a past interval [T-D,T] of aperture
(or length, duration) D and for the viable evolutions arriving at a prescribed
terminal state at the end of the temporal window (and thus telescoping if more
than one such evolutions exist). Hence, given time and duration dependent
evolutionary system and viability constraints, as well as time dependent
departure constraints, the Cournot map associates with any terminal time T and
state x the apertures D(T,x) of the intervals [T-D(T,x),T], the starting (or
initial) states at the beginning of the temporal window from which at least one
viable evolution will reach the given terminal state x at T. Cournot maps can
be used by a pursuer to intercept an evader's evolution in dynamic game theory.
After providing some properties of Cournot maps are next investigated, above
all, the regulation map piloting the viables evolutions at each time and for
each duration from the beginning of the temporal window up to terminal time.
The next question investigated is the selection of controls or regulons in the
regulation map whenever several of them exist. Selection processes are either
time dependent, when the selection operates at each time, duration and state
for selecting a regulon satisfying required properties (for instance, minimal
norm, minimal speed), or intertemporal. In this case, viable evolutions are
required to optimize some prescribed intertemporal functional, as in optimal
control. This generates value functions, the topics of the second part of this
study
