Abstract
We consider the problem u′(t)=H(u)(t)+Q(u)(t), u(a)=h(u), where H,Q:C([a,b];R)→L([a,b];R) are, in general, nonlinear
continuous operators, H∈ℋabαβ(g0,g1,p0,p1), and h:C([a,b];R)→R is a continuous functional. Efficient conditions sufficient for the
solvability and unique solvability of the problem considered are established.