摘要

The main results here are that (i) the P-0-frames are reflective in the category of all 0-dimensional frames, where a P-0-frame is a 0-dimensional frame in which any countable join of complemented elements is complemented, and (ii) the P-frames, meaning the completely regular frames in which every cozero element is complemented, are the same as the strongly 0-dimensional P-0-frames. In addition, it is shown that the Lindelof and the spatial P-0-frames are actually P-frames, but whether this holds for all P-0-frames remains open. Finally, a simple modification of the proof of (i) is described which provides a new proof that the P-frames are reflective in the category of all completely regular frames.

  • 出版日期2014-5-15