Are two 'teams' stronger than one? This 'rotation' of judges means that Christina Aguilera and Cee Lo Green will return alongside Adam Levine and Blake Shelton for season 5 in the fall -- while Usher and Shakira will take season 6 in the spring of 2014.
A rule or rule set is a statement that tells browsers how to render particular elements on an HTML page. A rule set consists of a selector followed by a declaration block. The selector selects the elements on an HTML page that are affected by the rule set.
empty set. The set with no elements. Empty Set. (or null set), the set that contains no elements. The concept of the empty set, like the concept of zero, arises from the need to have the result of any operation on sets also be a set.