The most well-known polarity items are those that are sensitive to negation and related expressions. These polarity items divide into those that must co-occur with a "somehow negative" expression ("negative polarity item", NPI) and those that cannot ("positive polarity item", PPI). An example of an NPI is the English word any. It is ungrammatical if it occurs in a sentence without a "negative" expression (A star "*" in front of a sentence means the sentence is believed to be ill-formed):
One says of an NPI like any that it is licensed by a negative expression. NPIs are also usually licensed by questions, as in:
An example of a PPI is the English word somewhat. If it occurs in a sentence with another negative expression, the sentence is ill-formed:
Much of the research on polarity items has centered around the question of what it takes for an expression to be "somehow negative". In the late seventies, William Ladusaw (building on work by Gilles Fauconnier) discovered that most NPIs are licensed in downward entailing environments. This is known as the Fauconnier-Ladusaw Hypothesis. A downward entailing environment, however, is not a necessary condition for an NPI to be licensed - they may be licensed by some non-monotone (and thus not downward entailing) contexts, like "exactly N", as well.
Different NPIs may be licensed by different expressions. Thus, while the NPI anything is licensed by the downward entailing expression at most two visitors, the idiomatic NPI lift a finger is not licensed by the same expression.
Wipo Publishes Patent of Johnson Controls Technology for "Prismatic Lithium Ion Cell with Positive Polarity Rigid Container" (American Inventors)
May 13, 2013; GENEVA, May 13 -- Publication No. WO/2013/066683 was published on May 10.Title of the invention: "PRISMATIC LITHIUM ION CELL WITH...
US Patent Issued to JVC Kenwood on Nov. 5 for "Liquid Crystal Display Device Having a Line Symmetric Arrangement of Circuit Elements and Lines in Positive-Polarity Signal Pixel Circuit Part and Negative-Polarity Signal Pixel Circuit Part of Each Pixel" (Japanese Inventor)
Nov 08, 2013; ALEXANDRIA, Va., Nov. 8 -- United States Patent no. 8,576,150, issued on Nov. 5, was assigned to JVC Kenwood Corp. (Yokohama-Shi,...
WIPO ASSIGNS PATENT TO PANASONIC FOR "DISPLAY PANEL DRIVING SEMICONDUCTOR INTEGRATED CIRCUIT, DISPLAY PANEL DRIVING MODULE AND DISPLAY APPARATUS" (AMERICAN INVENTORS)
May 03, 2011; GENEVA, May 3 -- Publication No. WO/2011/048723 was published on April 28. Title of the invention: "DISPLAY PANEL DRIVING...