Encyclopedia > 2020

  Article Content

2020



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Uniform structure

... : x in X }. if U is in Φ, then { (y, x) : (x, y) in U } is also in Φ if U is in Φ and V is a subset of X × X which contains U, then V is in Φ if ...