dbo:abstract
|
- In mathematical logic, a theory can be extended withnew constants or function names under certain conditions with assurance that the extension will introduceno contradiction. Extension by definitions is perhaps the best-known approach, but it requiresunique existence of an object with the desired property. Addition of new names can also be donesafely without uniqueness. Suppose that a closed formula is a theorem of a first-order theory . Let be a theory obtained from by extending its language with new constants and adding a new axiom . Then is a conservative extension of , which means that the theory has the same set of theorems in the original language (i.e., without constants ) as the theory . Such a theory can also be conservatively extended by introducing a new functional symbol: Suppose that a closed formula is a theorem of a first-order theory , where we denote . Let be a theory obtained from by extending its language with a new functional symbol (of arity ) and adding a new axiom . Then is a conservative extension of , i.e. the theories and prove the same theorems not involving the functional symbol ). Shoenfield states the theorem in the form for a new function name, and constants are the same as functionsof zero arguments. In formal systems that admit ordered tuples, extension by multiple constants as shown here can be accomplished by addition of a new constant tuple and the new constant names having the values of elements of the tuple. (en)
|
dbo:wikiPageID
| |
dbo:wikiPageLength
|
- 2618 (xsd:nonNegativeInteger)
|
dbo:wikiPageRevisionID
| |
dbo:wikiPageWikiLink
| |
dbp:wikiPageUsesTemplate
| |
dcterms:subject
| |
rdfs:comment
|
- In mathematical logic, a theory can be extended withnew constants or function names under certain conditions with assurance that the extension will introduceno contradiction. Extension by definitions is perhaps the best-known approach, but it requiresunique existence of an object with the desired property. Addition of new names can also be donesafely without uniqueness. Suppose that a closed formula is a theorem of a first-order theory . Let be a theory obtained from by extending its language with new constants and adding a new axiom . (en)
|
rdfs:label
|
- Extension by new constant and function names (en)
|
owl:sameAs
| |
prov:wasDerivedFrom
| |
foaf:isPrimaryTopicOf
| |
is dbo:wikiPageRedirects
of | |
is dbo:wikiPageWikiLink
of | |
is foaf:primaryTopic
of | |