The Index Set of Injectively Enumerable
✍
Stephan Wehner
📂
Article
📅
1994
🏛
John Wiley and Sons
🌐
English
⚖ 372 KB
## Abstract I introduce an effective enumeration of all effective enumerations of classes of r. e. sets and define with this the index set __IE__ of injectively enumerable classes. It is easy to see that this set is ∑~5~ in the Arithmetical Hierarchy and I describe a proof for the ∑~5~‐hardness of