Existence results are established for the equation y '' +f(t, y) = 0, 0 < t < 1. Here f may be singular in y and f is allowed to change sign. Our boundary data include y(0) = y'(1) + ky(1) = 0, k > -1 and y(0) = ...

Coincidence points for single and set valued maps are discussed in this paper. We show if F is essential and F congruent to G then G has a coincidence point.

Existence of a positive solution is established for second order boundary value problems on the semi-infinite interval.

The Schauder Tychonoff theorem in a locally convex topological space is used to establish existence results for Volterra-Hammmerstein and Hammerstein integral equations in a reflexive Banach space.