argmin definition
argmin means “pick any u at which the min is attained”; we restricted U to be assured that V˙(x, u) attains a min-
argmin means “pick any u at which the min is attained”; we restricted U to be assured that V˙ (x, u) attains a minimum). Note that the stabilization problem becomes, in these terms, a set of static nonlinear programming problems: minimize a function of u, for each x.