
In this article an example is constructed to show that Theorem 1.1 of L. Janos [Canad. Math. Bull. 18 (1975), no. 5, 675-678] is false. A proper formulation is obtained as follows. Theorem. If ( X , τ ) (X,\tau ) is a metrizable topological space, f : X → X f:X \to X is continuous, and a ∈ X a \in X , then the following statements are equivalent: (1) There exists a metric d compatible with τ \tau such that f is contractive with respect to d and the sequence ( f n ( x ) ) n = 1 ∞ ({f^n}(x))_{n = 1}^\infty converges to a for every x ∈ X x \in X . (2) The singleton {a} is an attractor for compact subsets under f. Furthermore, under this proper formulation, we show that Theorem 3.2 Janos [Proc. Amer. Math. Soc. 61 (1976), 161-175] and Theorem 2.3 Janos and J. L. Solomon [ibid. 71 (1978), 257-262], where the false Theorem 1.1 in [2] has been quoted in the original proofs, remain valid.
Fixed-point and coincidence theorems (topological aspects), Metric spaces, metrizability, attractors, fixed point theorem, Edelstein's contractivity, Special maps on metric spaces, metrizable topological space
Fixed-point and coincidence theorems (topological aspects), Metric spaces, metrizability, attractors, fixed point theorem, Edelstein's contractivity, Special maps on metric spaces, metrizable topological space
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