Idempotency of entailment
|This article does not cite any references or sources. (December 2009)|
||This article may be confusing or unclear to readers. (December 2006)|
Idempotency of entailment is a property of logical systems 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 structural rule called contraction and in such systems one may say that entailment is idempotent if and only if contraction is an admissible rule.
Rule of Contraction: from
A,C,C -> B
A,C -> B.
Or in sequent calculus notation,
|This logic-related article is a stub. You can help Wikipedia by expanding it.|