Statements (28)
| Predicate | Object |
|---|---|
| gptkbp:instanceOf |
mathematical hierarchy
|
| gptkbp:characterizedBy |
transfinite recursion
hyperarithmetical sets hyperjump operator |
| gptkbp:describes |
classification of sets of natural numbers
|
| gptkbp:field |
gptkb:logic
recursion theory |
| gptkbp:hasSubgroup |
gptkb:arithmetical_hierarchy
analytical hierarchy |
| https://www.w3.org/2000/01/rdf-schema#label |
hyperarithmetical hierarchy
|
| gptkbp:introduced |
gptkb:Kurt_Gödel
|
| gptkbp:level |
indexed by countable ordinals
|
| gptkbp:notation |
Δ^1_1 sets
Π^1_1 sets Σ^1_1 sets |
| gptkbp:relatedConcept |
hyperarithmetic set
lightface hierarchy recursive ordinal |
| gptkbp:relatedTo |
gptkb:arithmetical_hierarchy
analytical hierarchy |
| gptkbp:studiedIn |
gptkb:descriptive_set_theory
effective descriptive set theory |
| gptkbp:upperBound |
gptkb:Church–Kleene_ordinal
|
| gptkbp:usedIn |
gptkb:set_theory
computability theory |
| gptkbp:bfsParent |
gptkb:Kleene_hierarchy
gptkb:arithmetical_hierarchy |
| gptkbp:bfsLayer |
6
|