J Austral Math Soc Ser B 36 pp117--131, 1994.
(Received 14 January 1993; revised 10 March 1993)
In the paper we give sufficient conditions for the existence of a solution for a Darboux-Goursat optimization problem with a cost functional depending on the number of switchings of a control and the rapidity of its changes. An application is given to a gas absorption problem.