Characterizing (the largest countable set)
Authors: David Guaspari and Leo Harrington
Journal: Proc. Amer. Math. Soc. 57 (1976), 127-129
MSC: Primary 02K30
MathSciNet review: 0401476
Abstract: Assume projective determinacy. For any real , let is the type of a prewellordering of the reals which is in . Then, , the largest countable set of reals, is equal to is in . This result, which is true for all odd levels and generalizes a previously known characterization of , answers a question of Kechris.
Retrieve articles in Proceedings of the American Mathematical Society with MSC: 02K30
Retrieve articles in all journals with MSC: 02K30