Universal bounds and monotonicity of ordinal invariants

Boone, James R.

doi:10.1090/S0002-9939-1981-0627711-5

Universal bounds and monotonicity of ordinal invariants
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by James R. Boone

Proc. Amer. Math. Soc. 83 (1981), 641-644

DOI: https://doi.org/10.1090/S0002-9939-1981-0627711-5

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Abstract:

The tightness of a topological space provides a universal bound for all ordinal invariants determined by weak topologies generated by collections of subsets. All ordinal invariants are monotonic decreasing for pseudo-open mappings.

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