In mathematics, a quadratic algebra is a filtered algebra generated by degree one elements, with defining relations of degree 2. It was pointed out by Yuri Manin that such algebras play an important role in the theory of quantum groups. The most important class of graded quadratic algebras is Koszul algebras.
In mathematics, a quadratic algebra is a filtered algebra generated by degree two elements, with defining relations of degree 1.
A: No

A juvenile hacker who crippled an airport tower for six hours, damaged atown's phone system, and broke into pharmacy records has been charged in afirst-ever federal prosecution, the U.S. Attorney's office announcedtoday.
The accused is under age.
A: Yes

Wright sat out Wednesday's practice with an undisclosed injury, Mike Rothstein of ESPN.com reports. Wright joined injured fellow tight ends Eric Ebron (hamstring) and Cole Wick (undisclosed) on the sideline. The Rutgers product is competing with Wick, Darren Fells, and rookie Michael Roberts to back up presumed starter Ebron.
There's at least 3 people sitting on the sidelines injured.
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