翻訳と辞書
Words near each other
・ Destruction of Stocking Frames, etc. Act 1812
・ Destruction of Syria's chemical weapons
・ Destruction of the Country House exhibition
・ Destruction of the Library of Alexandria
・ Destruction of the Oberstift
・ Destruction of the Seven Cities
・ Destruction of the Thracian Bulgarians in 1913
・ Destruction of the Twelve Colonies
・ Destruction Ritual
・ Destruction Sound System
・ Destruction Sound System (2) (album)
・ Destruction under the Mongol Empire
・ Destruction, Inc.
・ Destructionism
・ Destructive device
Destructive dilemma
・ Destructive distillation
・ Destructive fishing practices
・ Destructive flour beetle
・ Destructive testing
・ Destructiveness (phrenology)
・ Destructo Doll
・ Destructo Trucks
・ Destructoid
・ Destructor
・ Destructor (computer programming)
・ Destrudo
・ Destry
・ Destry (band)
・ Destry (film)


Dictionary Lists
翻訳と辞書 辞書検索 [ 開発暫定版 ]
スポンサード リンク

Destructive dilemma : ウィキペディア英語版
Destructive dilemma

Destructive dilemma〔Hurley, Patrick. A Concise Introduction to Logic With Ilrn Printed Access Card. Wadsworth Pub Co, 2008. Page 361〕〔Moore and Parker〕 is the name of a valid rule of inference of propositional logic. It is the inference that, if ''P'' implies ''Q'' and ''R'' implies ''S'' and either ''Q'' is false or ''S'' is false, then either ''P'' or ''R'' must be false. In sum, if two conditionals are true, but one of their consequents is false, then one of their antecedents has to be false. ''Destructive dilemma'' is the disjunctive version of ''modus tollens''. The disjunctive version of ''modus ponens'' is the constructive dilemma. The rule can be stated:
:\frac
where the rule is that wherever instances of "P \to Q", "R \to S", and "\neg Q \or \neg S" appear on lines of a proof, "\neg P \or \neg R" can be placed on a subsequent line.
==Formal notation==
The ''destructive dilemma'' rule may be written in sequent notation:
: (P \to Q), (R \to S), (\neg Q \or \neg S) \vdash (\neg P \or \neg R)
where \vdash is a metalogical symbol meaning that \neg P \or \neg R is a syntactic consequence of P \to Q, R \to S, and \neg Q \or \neg S in some logical system;
and expressed as a truth-functional tautology or theorem of propositional logic:
:(((P \to Q) \and (R \to S)) \and (\neg Q \or \neg S)) \to (\neg P \or \neg R)
where P, Q, R and S are propositions expressed in some formal system.

抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)
ウィキペディアで「Destructive dilemma」の詳細全文を読む



スポンサード リンク
翻訳と辞書 : 翻訳のためのインターネットリソース

Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.