On common fixed points of compatible mappings in metric and Banach spaces.
Let be a closed convex subset of a complete convex metric space and two compatible mappings satisfying following contraction definition: for all in , where and . If is continuous and contains , then and have a unique common fixed point in and at this point is continuous. This result gives affirmative answers to open questions set forth by Diviccaro, Fisher and Sessa in connection with necessarity of hypotheses of linearity and non-expansivity of in their Theorem [3]...