基本邏輯名詞

2009/02/25
~ 阿亮 ~

最近看到一些簡單的邏輯 (Logic) 英詞名詞,並不是很清楚,所以,找出來再複習一下。

其實大部份是很簡單的,只是換成英文就不熟了.

Rules of Inference

 Modus Ponens

\displaystyle\begin{array}{l}
p\rightarrow q \\
p \\
\therefore q
\end{array}

 

 Modus Tollens

\begin{array}{l}
p\rightarrow q \\
\neg q \\
\therefore \,\neg p
\end{array}

 

 Hypothetical Syllogism

\begin{array}{l}
p\rightarrow q \\
q\rightarrow r \\
\therefore p\rightarrow r
\end{array}

 

 Disjunctive Syllogism

\begin{array}{l}
p\vee q \\
\neg p \\
\therefore q
\end{array}

 Constructive Dilemma

\begin{array}{l}
(p\rightarrow q) \wedge (r\rightarrow s) \\
p\vee r \\
\therefore q\vee s
\end{array}

 

 Absorption

\begin{array}{l}
\,\\
p\rightarrow q \\
\therefore p\rightarrow (p\wedge q)
\end{array}

 Simplification

\begin{array}{l}
\\
p\wedge q \\
\therefore p
\end{array}

 

 Conjunction

\begin{array}{l}
p \\
q \\
\therefore p\wedge q
\end{array}

 

 Addition

\begin{array}{l}
\\
p \\
\therefore p \vee q
\end{array}

 

 

Rules of Replacement

Double Negation p\leftrightarrow \,\neg\neg p
Commutation \begin{array}{l} \\  (p\vee q)\leftrightarrow  (q\vee p) \\ (p\wedge q)\leftrightarrow  (q\wedge p) \\ \end{array}
Tautology \begin{array}{l} \\  p\leftrightarrow  (p\vee p) \\ p\leftrightarrow  (p\wedge p) \\ \end{array}
Association

\begin{array}{l} \\ \left[p\vee  (q\vee r)\right] \leftrightarrow  \left[(p\vee  q)\vee r\right] \\  \left[p\wedge  (q\wedge r)\right] \leftrightarrow  \left[(p\wedge  q)\wedge r\right] \\ \end{array}

Transposition \begin{array}{l} \\  (p\rightarrow q) \leftrightarrow  (\neg q\rightarrow \neg p) \\ \end{array}
Material Implication \begin{array}{l} \\  (p\rightarrow q) \leftrightarrow  (\neg p\vee q) \\ \end{array}
Exportation  \begin{array}{l} \\  \left[(p\wedge q)\rightarrow r }\right]  \leftrightarrow   \left[p\rightarrow (q\rightarrow r)\right]   \\ \end{array}
Material Equivalence

\begin{array}{l} \\
(p\leftrightarrow q)\leftrightarrow \left[(p\rightarrow q) \wedge (q\rightarrow p)\right] \\
 (p\leftrightarrow q)\leftrightarrow \left[(p\wedge q) \vee (\neg p \,\wedge \neg q)\right] \\
\end{array}

Distribution

\begin{array}{l} \\
\left[p \wedge (q\vee r)\left] \leftrightarrow \left[(p\wedge q)\vee (p\wedge r)\right] \\
\left[p \vee (q\wedge r)\left] \leftrightarrow \left[(p\vee q)\wedge (p\vee r)\right] \\
\end{array}

De Morgan’s Theorems

\begin{array}{l} \\
\neg(p \wedge q)\leftrightarrow (\neg p \,\vee \neg q) \\
\neg(p \vee q)\leftrightarrow (\neg p \,\wedge \neg q) \\
\end{array}

 

 

Bi-conditionals Logical Equivalence

(\forall x)(\psi x\rightarrow \varphi x) \leftrightarrow  \,\neg(\exists x)(\psi x \,\wedge \neg\varphi x)

"Everything in the lake is wet." 

is logically equivalent to

"There isn’t anything in the lake which is not wet."

 

(\exists x)(\psi x\wedge \varphi x) \leftrightarrow  \,\neg(\forall x)(\psi x \rightarrow \,\neg\varphi x)

"There exists at least one individual who is both a native of Boston and of Irish descent."

is logically equivalent to

"It’s not true that no natives of Boston are of Irish descent."

 

(\forall x)(\psi x\rightarrow \neg\varphi x) \leftrightarrow \,\neg(\exists x)(\psi x \wedge \varphi x)

"No residents of Boston are Irish."

is logically equivalent to

"It’s not true that some residents of Boston are Irish."

 

(\exists x)(\psi x \,\wedge \neg\varphi x) \leftrightarrow \,\neg(\forall x)(\psi x \rightarrow \varphi x)

 "Some residents of Boston are not Irish."

is logically equivalent to

"Not all residents of Boston are Irish."

 

 

 



站內搜尋



本站其他服務

本站其他軟體



  • 油價快訊App (OilPrices)

    依據油價及匯率,估算台灣下週油價,另外提供三週、一年以及三年的歷史變化,以及週末下午推播通知最新油價預估或公告。


  • 批踢踢快訊 (pttNews)

    身為鄉民的您,是不是常常覺得現在的批踢踢 (PTT) 閱讀器,明明您就只要看幾個板,都幫您分類好,但不是您要的?甚至您只想關注某個人(或某件事)的消息,卻散布在不同東西,找出來很辛苦? 這個 App 可以解決您這些問題,快來用吧!


  • 條碼掃描器(QRCode)

    支援 QRCode and Barcodes、可連續快速掃描、自動對焦、可打開手電筒供掃描時使用


  • 台灣空污警報(AirInfo)

    設定特定站點為推播通知關注點後,當該站點空氣品質變糟時,即時推播通知給您。另外提供站點附近基本天氣預測資料。


  • 當令蔬果花卉(AgriInfo)

    是不是常常在超市看到水果蔬菜的價格,總是不確定是當季蔬果?這個服務就是幫你很快判斷眼前的蔬果花卉的價格是否便宜。


  • 下一班公車(nextBus)

    這個 app 只要開啟後,就根據定位幫你過濾出附近站牌的時刻表,以及提供相關公車預計到站的時間,方便您在很快時間內確定要坐的哪一班公車