Fixed point uniqueness of generalized (ψ, φ)-weak contractions in partially ordered metric spaces under suitable constraints

In this paper, by providing an example, I show that the condition which produced by Radenovi´c and Kadelburg in [Generalized weak contractions in partially ordered metric spaces, Comput. Math. Appl. 60 (2010) pp. 1776-1783] is not sufficient for uniqueness of the fixed point. Furthermore, a new sufficient condition is introduced for the uniqueness of the fixed point. Some suitable examples are furnished to demonstrate the validity of the hypotheses of my results.