R.A. Brualdi, A.J. Hoffman
Linear Algebra and Its Applications
We show that (θ) implies that there is a first countable < θ- collectionwise Hausdorff space that is not weakly θ-collectionwise Hausdorff. We also show that in the model obtained by Levy collapsing a weakly compact (supercompact) cardinal to ω2, first countable collectionwise Hausdorff spaces are weakly collectionwise Hausdorff (weakly collectionwise Hausdorff). In the last section we show that assuming a certain θ-family of integer-valued functions exists and that in the model obtained by Levy collapsing a supercompact cardinal to ω these families do not exist. © 1994 American Mathematical Society.
R.A. Brualdi, A.J. Hoffman
Linear Algebra and Its Applications
Peter Wendt
Electronic Imaging: Advanced Devices and Systems 1990
Vladimir Yanovski, Israel A. Wagner, et al.
Ann. Math. Artif. Intell.
Michael E. Henderson
International Journal of Bifurcation and Chaos in Applied Sciences and Engineering