Über zwei Bezeichnungssysteme für Ordinalzahlen.
Über zwei Sätze von G. Fichtenholz und L. Kantorovitch
Ueber den allgemeinen Functionsbegriff und dessen Darstellung durch eine willkürliche Curve
Ueber den grössten gemeinsamen Factor
Ueber die Auflösung linearer Gleichungen mit reellen Coefficienten
Ueber die von drei Moduln erzeugte Dualgruppe
Ueber ein Princip der Zuordnung algebraischer Formen.
Ultra -ideals in lattice implication algebras
We define an ultra -ideal of a lattice implication algebra and give equivalent conditions for an -ideal to be ultra. We show that every subset of a lattice implication algebra which has the finite additive property can be extended to an ultra -ideal.
Ultra -Ideals in lattice implication algebras and -algebras
A mistake concerning the ultra -ideal of a lattice implication algebra is pointed out, and some new sufficient and necessary conditions for an -ideal to be an ultra -ideal are given. Moreover, the notion of an -ideal is extended to -algebras, the notions of a (prime, ultra, obstinate, Boolean) -ideal and an -ideal of an -algebra are introduced, some important examples are given, and the following notions are proved to be equivalent in -algebra: (1) prime proper -ideal and Boolean -ideal,...
Ultrafilter extensions of asymptotic density
We characterize for which ultrafilters on is the ultrafilter extension of the asymptotic density on natural numbers -additive on the quotient boolean algebra or satisfies similar additive condition on . These notions were defined in [Blass A., Frankiewicz R., Plebanek G., Ryll-Nardzewski C., A Note on extensions of asymptotic density, Proc. Amer. Math. Soc. 129 (2001), no. 11, 3313–3320] under the name (null) and (*). We also present a characterization of a - and semiselective ultrafilters...
Ultrafilter with predecessors in Rudin-Frolík order
Ultrafilters and endomorphic universes
Ultrafilters of sets
Ultrafilters over measurable cardinals
Ultrafilters without immediate predecessors in Rudin-Frolík order
Ultrafiltres absolus et problèmes d'extraction de sous-suites
Ultralogics and probability models.
Ultrapowers and Boolean ultrapowers of ... and ...1.
Ultrapowers of unbounded selfadjoint operators
Ultraproducts and Approximation in Local Rings I.