𝔖 Bobbio Scriptorium
✦   LIBER   ✦

σ-fields of bad Borel sets

✍ Scribed by A.H. Stone

Publisher
Elsevier Science
Year
1998
Tongue
English
Weight
376 KB
Volume
82
Category
Article
ISSN
0166-8641

No coin nor oath required. For personal study only.

✦ Synopsis

A "bad Bore1 subfield" of a space X is an infinite countably g-generated u-subfield of Bore1 sets none of which (other than 8 and X) is open or closed. X has "very bad Bore1 subfields" if, for each countable ordinal CY, there is such a field of Bore1 sets none of which (other than 0 and X) is of Bore1 class less than (Y. Under suitable conditions on X, such fields are constructed, and a possible alternative construction is discussed.

📜 SIMILAR VOLUMES

The normal form of Borel sets. Part II:
The normal form of Borel sets. Part II: Borel sets of infinite rank
✍ Jacques Duparc 📂 Article 📅 1999 🏛 Elsevier Science 🌐 English ⚖ 459 KB

## RBsumC. For each Bore1 set of reals of infinite rank A we obtain u "normal form" of A by finding a Bore1 set 62 such that A and 6! continuously reduce to each other. We do so by defining simple Bore1 operations which are homomorphic to the w, first Veblen ordinal operations of base (J, required