(1) Department of Methematics, The University of Iowa, Iowa City, IA 52242, USA
Abstract:
The Baire category theorem for compact Hausdorff spaces is used to show that any recursive completion ℬϕof the countable atomless Boolean algebra ℬ is ℬrecursively closed." Also, a theorem of R.D. Anderson on the simplicity of
Aut(ℬ) is used to show that uncountably many automorphisms of ℬ extend to ℬϕ.
This revised version was published online in June 2006 with corrections to the Cover Date.