Tautology may refer to:
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Tautology (language)
In literary criticism and rhetoric, a tautology is a statement that repeats an idea using near-synonymous morphemes, words or phrases, effectively "saying the same thing twice". Tautology and pleonasm are not consistently differentiated in lite ...
, a redundant statement in literature and rhetoric
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Tautology (logic)
In mathematical logic, a tautology (from ) is a formula that is true regardless of the interpretation of its component terms, with only the logical constants having a fixed meaning. For example, a formula that states, "the ball is green or the ...
, in formal logic, a statement that is true in every possible interpretation
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Tautology (rule of inference)
In propositional logic, tautology is either of two commonly used rules of replacement. The rules are used to eliminate redundancy in disjunctions and conjunctions when they occur in logical proofs. They are:
The principle of idempotency of d ...
, a rule of replacement for logical expressions
See also
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Pleonasm
Pleonasm (; , ) is redundancy in linguistic expression, such as "black darkness", "burning fire", "the man he said", or "vibrating with motion". It is a manifestation of tautology by traditional rhetorical criteria. Pleonasm may also be used f ...
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Redundancy (disambiguation)
Redundancy or redundant may refer to:
Language
* Redundancy (linguistics), information that is expressed more than once
Engineering and computer science
* Data redundancy, database systems which have a field that is repeated in two or more table ...
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Tautological (disambiguation)
In mathematics, tautological may refer to:
Logic:
* Tautological consequence
Geometry, where it is used as an alternative to canonical:
*Tautological bundle
*Tautological one-form
* Tautology (grammar), unnecessary repetition, or more words than ...
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Tautonym
A tautonym is a scientific name of a species in which both parts of the name have the same spelling, such as '' Rattus rattus''. The first part of the name is the name of the genus and the second part is referred to as the ''specific epithet'' i ...
, a scientific name of a species in which both parts of the name have the same spelling
{{Disambiguation
hu:Tautológia#Nyelvtudományi és irodalmi tautológia