Several results are presented concerning the existence or nonexistence, for a subset S of ? , of a real r which works as a robust code for S with respect to a given sequence of pairwise disjoint stationary subsets of ? , where "robustness" of r as a code may either mean that S ? L[r, ] whenever each S * is equal to S modulo nonstationary changes, or may have the weaker meaning that S ? L[r, ] for every club C ? ? . Variants of the above theme are also considered which result when the requirement that S gets exactly coded is replaced by the weaker requirement that some set is coded which is equal to S up to a club, and when sequences of stationary sets are replaced by decoding devices possibly carrying more information (like functions from ? into ? ).
|Number of pages||17|
|Publication status||Published - 1 Jan 2005|
- ℙ max extensions of L(ℝ)
- Forcing axioms
- Robust codes for subsets of ω 1
- Sequences of stationary subsets of ω 1