Notes on strongly Whyburn spaces
We introduce the notion of a strongly Whyburn space, and show that a space is strongly Whyburn if and only if is Whyburn. We also show that if is Whyburn for any Whyburn space , then is discrete.
We introduce the notion of a strongly Whyburn space, and show that a space is strongly Whyburn if and only if is Whyburn. We also show that if is Whyburn for any Whyburn space , then is discrete.
The following statement is proved to be independent from : Let be a Tychonoff space with and . Then a union of less than of nowhere dense subsets of is a union of not greater than of nowhere dense subsets.