The Baire Category of Subsequences and Permutations which preserve Limit Points

2020 
Let $$\mathcal {I}$$ be a meager ideal on $$\mathbf {N}$$ . We show that if x is a sequence with values in a separable metric space then the set of subsequences [resp. permutations] of x which preserve the set of $$\mathcal {I}$$ -cluster points of x is topologically large if and only if every ordinary limit point of x is also an $$\mathcal {I}$$ -cluster point of x. The analogue statement fails for all maximal ideals. This extends the main results in [Topology Appl. 263 (2019), 221–229]. As an application, if x is a sequence with values in a first countable compact space which is $$\mathcal {I}$$ -convergent to $$\ell $$ , then the set of subsequences [resp. permutations] which are $$\mathcal {I}$$ -convergent to $$\ell $$ is topologically large if and only if x is convergent to $$\ell $$ in the ordinary sense. Analogous results hold for $$\mathcal {I}$$ -limit points, provided $$\mathcal {I}$$ is an analytic P-ideal.
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