ABSTRACT
We remark that a similar theorem may be proved also in case p = 1. Here (7.62) and (7.63) have to be replaced by the conditions
{ signz(s) if z(s) tf 0,
z+(t,s) = sign f(t, s) if xes) =0,
and l b[A(t)z(s) + f(t,s»)z_(t,s) ds >° with
{ sign z(s) if z(s) tf 0,
respectively.
