from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A proper filter which has a law of dichotomy for complements.
  • n. A filter (subset of a poset) that is maximal as a set with respect to the definition of proper filter.


Sorry, no etymologies found.


  • "ultrafilter", and thereby split it up into two fractions (a filtrate and a sediment that did not pass through the filter), the curious state of things occurred that neither of these fractions was any longer able to bring about fermentation, but that after being mixed with one another they recovered that capacity.

    Nobel Prize in Chemistry 1929 - Presentation Speech

  • If the ultrafilter U is nonprincipal, i.e. contains no finite sets, then the diagonal map is not onto the domain of

    First-order Model Theory

  • If we have an ultrafilter U over I, then we can construct a reduced product from C by making two elements of

    First-order Model Theory

  • C equivalent if and only if the set of indices at which they are equal is a set in the ultrafilter U.

    First-order Model Theory

  • The patented dual stage cold sterilization ultrafilter has the capability to filter out bacteria and, due to its exceptional filtration levels, filter out many viruses, parasites and biotoxins.

  • Nephros's proprietary dual stage cold sterilization ultrafilter will form the basis of the portable system.

  • Nephros ultrafilter technology has also been selected for further development by the U.S. Marine Corps for purification of drinking water by soldiers in the field.

  • The Army has not to date issued a Request For Proposal RFP, and Nephros has no information regarding when or if an RFP applicable to the UF-40 ultrafilter may be put forth by the U.S. Army.

  • In response to a Request For Information RFI from the U.S. Army, Nephros submitted its UF-40 ultrafilter for consideration as part of the standard issue hydration pack for soldiers in the field.

  • Nephros 'proprietary dual stage cold sterilization ultrafilter will form the basis of the portable system.



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