“…The above setting subsumes the classical infinite horizon optimal control problem when f and U are time independent, L(t, x, u) = e −λt (x, u) for some mapping : R n × R m → R + and λ > 0, t 0 = 0. Infinite horizon problems exhibit many phenomena not arising in the context of finite horizon problems and their study is still going on, even in the absence of state constraints, see [1,2,3,4,5,6,33,36,37,38,40,43,44] and their bibliographies. Among such phenomena let us recall that already in 70ies Halkin, see [32] and also [36], observed that in the necessary optimality conditions for an infinite horizon problem it may happen that the co-state of the maximum principle is different from zero at infinity and that only abnormal maximum principles hold true (even for problems without state constraints).…”