Cohen algebra

Not to be confused with Cohen ring or Rankin–Cohen algebra.
For the quotient of the algebra of Borel sets by the ideal of meager sets, sometimes called the Cohen algebra, see Cantor algebra.

In mathematical set theory, a Cohen algebra, named after Paul Cohen, is a type of Boolean algebra used in the theory of forcing. A Cohen algebra is a Boolean algebra whose completion is isomorphic to the completion of a free Boolean algebra (Koppelberg 1993).