An algebraic and logical approach to continuous images
We prove that a Boolean algebra is countable iff its subalgebra lattice admits a continuous complementation.
In the present paper we deal with the relations between direct product decompositions of a directed set and direct product decompositions of intervals of .
We study conditions on automorphisms of Boolean algebras of the form (where λ is an uncountable cardinal and is the ideal of sets of cardinality less than κ ) which allow one to conclude that a given automorphism is trivial. We show (among other things) that every automorphism of which is trivial on all sets of cardinality κ⁺ is trivial, and that implies both that every automorphism of (ℝ)/Fin is trivial on a cocountable set and that every automorphism of (ℝ)/Ctble is trivial.
The aim of this paper is to show that every infinite Boolean algebra which admits a countable minimally acting group contains a dense projective subalgebra.
We consider four combinatorial interpretations for the algebra of Boolean differential operators and construct, for each interpretation, a matrix representation for the algebra of Boolean differential operators.