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that states that one may derive the same consequences from many instances of a hypothesis as from just one. This property can be captured by a
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260:{\displaystyle {\frac {\Gamma ,C,C\vdash B}{\Gamma ,C\vdash B}}}
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143:, and in such systems one may say that
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817:. You can help Knowledge (XXG) by
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151:if and only if contraction is an
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278:, entailment is not idempotent.
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869:Theorems in propositional logic
783:Tractatus Logico-Philosophicus
388:Problem of multiple generality
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773:The Principles of Mathematics
469:Commutativity of conjunction
63:"Idempotency of entailment"
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489:Monotonicity of entailment
158:Rule of contraction: from
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378:Idempotency of entailment
127:Idempotency of entailment
737:Willard Van Orman Quine
813:-related article is a
712:Charles Sanders Peirce
555:Hypothetical syllogism
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778:Principia Mathematica
550:Disjunctive syllogism
535:modus ponendo tollens
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768:Function and Concept
540:Constructive dilemma
515:Material implication
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44:improve this article
864:Logical consequence
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288:No-deleting theorem
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104:December 2009
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29:This article
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819:expanding it
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702:Hugh MacColl
677:Georg Cantor
672:George Boole
569:Introduction
525:modus ponens
453:Higher-order
448:Second-order
398:Distribution
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358:Truth tables
276:affine logic
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42:Please help
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874:Logic stubs
647:Disjunction
642:Conjunction
627:Existential
615:Elimination
606:Disjunction
601:Conjunction
586:Existential
443:First-order
368:Truth value
338:Quantifiers
180:is derived
140:contraction
858:Categories
697:Kurt Gödel
560:Absorption
462:Principles
348:Connective
203:notation,
149:idempotent
145:entailment
74:newspapers
632:Universal
591:Universal
494:Explosion
479:Bivalence
408:Soundness
353:Tautology
343:Predicate
249:⊢
240:Γ
232:⊢
217:Γ
31:does not
576:Negation
403:Validity
383:Logicism
282:See also
331:General
137:called
88:scholar
52:removed
37:sources
660:People
272:linear
199:Or in
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809:This
756:Works
503:Rules
95:JSTOR
81:books
815:stub
433:Term
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67:news
35:any
33:cite
270:In
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