In mathematics a quantity is said to be invariant if its value does not change following a given operation. For instance, multiplication of any real number by the identity element (1) leaves it unchanged. Thus, all real numbers are invariant under the...

In mathematics, an invariant is something that does not change under a set of transformations. The property of being an invariant is invariance. Mathematicians say that a quantity is invariant "under" a transformation; some economists say it is...

Parent to child: "You grew almost an inch this month! If you keep growing that fast, how tall will you be when you're my age?" You are traveling with a child in a car. It's a long trip and you are passed by...

A semantics-preserving exchange of information between two software applications requires mappings between logically equivalent concepts in the ontology of each application. The challenge of semantic integration is therefore equivalent to the problem of generating such mappings, determining that they are correct, and providing a...

Journalism: One of the assertions that the media make most often about the U.S. economy is that President Bush's tax cuts didn't do what he promised. But the data clearly show nothing could be farther from the truth.Bush lowered taxes in both 2001 and 2003....

The head of the East Side's venerable Lexington Democratic Club, Alex Tisch, sent out an email yesterday concerning ground rules for the group's future meetings. Apparently, things are getting a little out of hand up there. The behavior of some members of the Executive Committee...