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Keywords:
tightness; fan-tightness; countably compact spaces; pseudo-compact space; P-point; biquotient mapping
tightness; fan-tightness; countably compact spaces; pseudo-compact space; P-point; biquotient mapping
Summary:
Countable tightness is compared to the stronger notion of countable fan-tight\-ness. In particular, we prove that countable tightness is equivalent to countable fan-tightness in countably compact regular spaces, and that countable fan-tightness is preserved by pseudo-open compact mappings. We also discuss the behaviour of countable tightness and of countable fan-tightness under the product operation.
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