翻訳と辞書
Words near each other
・ Universal Exposition of Wines and Spirits
・ Universal Express
・ Universal Express Pass
・ Universal extra dimension
・ Universal Fighting System
・ Universal File Format
・ Universal Flash Storage
・ Universal Flowering
・ Universal football
・ Universal force field
・ Universal Forest Products
・ Universal Forum of Cultures
・ Universal Foundation for Better Living
・ Universal Games
・ Universal gateway
Universal generalization
・ Universal Genève
・ Universal geometric algebra
・ Universal grammar
・ Universal graph
・ Universal Graphics Module
・ Universal Great Brotherhood
・ Universal grinder
・ Universal Groove
・ Universal Gym Equipment
・ Universal Hall
・ Universal Hall Pass
・ Universal Handy Interface
・ Universal Hartland Visual Effects
・ Universal hashing


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

Universal generalization : ウィキペディア英語版
Universal generalization

In predicate logic, generalization (also universal generalization or universal introduction,〔Copi and Cohen〕〔Hurley〕〔Moore and Parker〕 GEN) is a valid inference rule. It states that if \vdash P(x) has been derived, then \vdash \forall x \, P(x) can be derived.
==Generalization with hypotheses==
The full generalization rule allows for hypotheses to the left of the turnstile, but with restrictions. Assume Γ is a set of formulas, \varphi a formula, and \Gamma \vdash \varphi(y) has been derived. The generalization rule states that \Gamma \vdash \forall x \varphi(x) can be derived if ''y'' is not mentioned in Γ and ''x'' does not occur in \varphi.
These restrictions are necessary for soundness. Without the first restriction, one could conclude \forall x P(x) from the hypothesis P(y). Without the second restriction, one could make the following deduction:
#\exists z \exists w ( z \not = w) (Hypothesis)
#\exists w (y \not = w) (Existential instantiation)
#y \not = x (Existential instantiation)
#\forall x (x \not = x) (Faulty universal generalization)
This purports to show that \exists z \exists w ( z \not = w) \vdash \forall x (x \not = x), which is an unsound deduction.

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「Universal generalization」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.