Title
Types for hereditary head normalizing terms
Abstract
Klop's Problem is finding a type for characterizing hereditary head normalizing terms, that is, lambda-terms whose Böhm trees do not contain the bottom. This paper proves that this problem does not have any solution by showing that the set of those terms is not recursively enumerable. This paper also gives a best-possible solution by providing an intersection type system with a countably infinite set of types such that typing in all these types characterizes hereditary head normalizing terms. By using the same technique, this paper also shows that the set of lambda-terms normalizing by infinite reduction is not recursively enumerable.
Year
DOI
Venue
2008
10.1007/978-3-540-78969-7_15
FLOPS
Keywords
Field
DocType
recursively enumerable,hereditary head,best-possible solution,infinite reduction,hm tree,countably infinite,intersection type system
Countable set,Maximal set,Computer science,Recursively enumerable language,Algorithm,Recursive functions,Transitive closure
Conference
Volume
ISSN
ISBN
4989
0302-9743
3-540-78968-5
Citations 
PageRank 
References 
2
0.65
8
Authors
1
Name
Order
Citations
PageRank
Makoto Tatsuta111122.36