... closed, convex, and invariant under T by (H2) and the propertiesof linearity and continuity of the inner product, so that, by the Schauder fixed pointtheorem, T will have a fixed point in C if it ... hand, for an≥ 0, our hypothesesare more general than those in [16] since (GM1) implies that f is str ictly increasing, while(H3) does not.We wonder whether the mentioned result by Grace and ... MTM2007-60854 and MTM2006-26627-E) and regional Andalusian (Grants FQM210 and P06-FQM01504)Governments.References[1] R. P. Agarwal, Difference Equat ions and Inequalities: Theory, Methods, and Applications,...