Difference between revisions of "Truth table"
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− | A '''truth table''' is a tabular array that illustrates the computation of a [[boolean function]], that is, a function of the form <math>f : \mathbb{B}^k \to \mathbb{B},</math> where <math>k\!</math> is a non-negative integer and <math>\mathbb{B}</math> is the [[boolean domain]] <math>\{ 0, 1 \}.\!</math> | + | <font size="3">☞</font> This page belongs to resource collections on [[Logic Live|Logic]] and [[Inquiry Live|Inquiry]]. |
+ | |||
+ | A '''truth table''' is a tabular array that illustrates the computation of a ''logical function'', that is, a function of the form <math>f : \mathbb{A}^k \to \mathbb{A},</math> where <math>k\!</math> is a non-negative integer and <math>\mathbb{A}</math> is the domain of logical values <math>\{ \operatorname{false}, \operatorname{true} \}.</math> The names of the logical values, or ''truth values'', are commonly abbreviated in accord with the equations <math>\operatorname{F} = \operatorname{false}</math> and <math>\operatorname{T} = \operatorname{true}.</math> | ||
+ | |||
+ | In many applications it is usual to represent a truth function by a [[boolean function]], that is, a function of the form <math>f : \mathbb{B}^k \to \mathbb{B},</math> where <math>k\!</math> is a non-negative integer and <math>\mathbb{B}</math> is the [[boolean domain]] <math>\{ 0, 1 \}.\!</math> In most applications <math>\operatorname{false}</math> is represented by <math>0\!</math> and <math>\operatorname{true}</math> is represented by <math>1\!</math> but the opposite representation is also possible, depending on the overall representation of truth functions as boolean functions. The remainder of this article assumes the usual representation, taking the equations <math>\operatorname{F} = 0</math> and <math>\operatorname{T} = 1</math> for granted. | ||
==Logical negation== | ==Logical negation== | ||
− | '''[[Logical negation]]''' is an | + | '''[[Logical negation]]''' is an operation on one logical value, typically the value of a proposition, that produces a value of ''true'' when its operand is false and a value of ''false'' when its operand is true. |
− | The truth table of | + | The truth table of <math>\operatorname{NOT}~ p,</math> also written <math>\lnot p,\!</math> appears below: |
<br> | <br> | ||
− | {| align="center" border="1" cellpadding="8" cellspacing="0" style=" | + | {| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:45%" |
− | |+ | + | |+ style="height:30px" | <math>\text{Logical Negation}\!</math> |
− | |- style="background:# | + | |- style="height:40px; background:#f0f0ff" |
− | + | | style="width:50%" | <math>p\!</math> | |
− | + | | style="width:50%" | <math>\lnot p\!</math> | |
|- | |- | ||
− | | F || T | + | | <math>\operatorname{F}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | T || F | + | | <math>\operatorname{T}</math> || <math>\operatorname{F}</math> |
|} | |} | ||
<br> | <br> | ||
− | The | + | The negation of a proposition <math>p\!</math> may be found notated in various ways in various contexts of application, often merely for typographical convenience. Among these variants are the following: |
<br> | <br> | ||
− | {| align="center" border="1" cellpadding="8" cellspacing="0" | + | {| align="center" border="1" cellpadding="8" cellspacing="0" width="45%" |
− | |+ | + | |+ style="height:30px" | <math>\text{Variant Notations}\!</math> |
− | |- style="background:# | + | |- style="height:40px; background:#f0f0ff" |
− | + | | width="50%" align="center" | <math>\text{Notation}\!</math> | |
− | ! | + | | width="50%" | <math>\text{Vocalization}\!</math> |
|- | |- | ||
− | | | + | | align="center" | <math>\bar{p}\!</math> |
− | | bar | + | | <math>p\!</math> bar |
|- | |- | ||
− | | | + | | align="center" | <math>\tilde{p}\!</math> |
− | | | + | | <math>p\!</math> tilde |
|- | |- | ||
− | | | + | | align="center" | <math>p'\!</math> |
− | | bang | + | | <math>p\!</math> prime<br> <math>p\!</math> complement |
+ | |- | ||
+ | | align="center" | <math>!p\!</math> | ||
+ | | bang <math>p\!</math> | ||
|} | |} | ||
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==Logical conjunction== | ==Logical conjunction== | ||
− | '''[[Logical conjunction]]''' is an | + | '''[[Logical conjunction]]''' is an operation on two logical values, typically the values of two propositions, that produces a value of ''true'' if and only if both of its operands are true. |
− | The truth table of | + | The truth table of <math>p ~\operatorname{AND}~ q,</math> also written <math>p \land q\!</math> or <math>p \cdot q,\!</math> appears below: |
<br> | <br> | ||
− | {| align="center" border="1" cellpadding="8" cellspacing="0" style=" | + | {| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:45%" |
− | |+ | + | |+ style="height:30px" | <math>\text{Logical Conjunction}\!</math> |
− | |- style="background:# | + | |- style="height:40px; background:#f0f0ff" |
− | + | | style="width:33%" | <math>p\!</math> | |
− | + | | style="width:33%" | <math>q\!</math> | |
− | + | | style="width:33%" | <math>p \land q</math> | |
|- | |- | ||
− | | F || F || F | + | | <math>\operatorname{F}</math> || <math>\operatorname{F}</math> || <math>\operatorname{F}</math> |
|- | |- | ||
− | | F || T || F | + | | <math>\operatorname{F}</math> || <math>\operatorname{T}</math> || <math>\operatorname{F}</math> |
|- | |- | ||
− | | T || F || F | + | | <math>\operatorname{T}</math> || <math>\operatorname{F}</math> || <math>\operatorname{F}</math> |
|- | |- | ||
− | | T || T || T | + | | <math>\operatorname{T}</math> || <math>\operatorname{T}</math> || <math>\operatorname{T}</math> |
|} | |} | ||
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==Logical disjunction== | ==Logical disjunction== | ||
− | '''[[Logical disjunction]]''', also called '''logical alternation''', is an | + | '''[[Logical disjunction]]''', also called '''logical alternation''', is an operation on two logical values, typically the values of two propositions, that produces a value of ''false'' if and only if both of its operands are false. |
− | The truth table of | + | The truth table of <math>p ~\operatorname{OR}~ q,</math> also written <math>p \lor q,\!</math> appears below: |
<br> | <br> | ||
− | {| align="center" border="1" cellpadding="8" cellspacing="0" style=" | + | {| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:45%" |
− | |+ | + | |+ style="height:30px" | <math>\text{Logical Disjunction}\!</math> |
− | |- style="background:# | + | |- style="height:40px; background:#f0f0ff" |
− | + | | style="width:33%" | <math>p\!</math> | |
− | + | | style="width:33%" | <math>q\!</math> | |
− | + | | style="width:33%" | <math>p \lor q</math> | |
|- | |- | ||
− | | F || F || F | + | | <math>\operatorname{F}</math> || <math>\operatorname{F}</math> || <math>\operatorname{F}</math> |
|- | |- | ||
− | | F || T || T | + | | <math>\operatorname{F}</math> || <math>\operatorname{T}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | T || F || T | + | | <math>\operatorname{T}</math> || <math>\operatorname{F}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | T || T || T | + | | <math>\operatorname{T}</math> || <math>\operatorname{T}</math> || <math>\operatorname{T}</math> |
|} | |} | ||
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==Logical equality== | ==Logical equality== | ||
− | '''[[Logical equality]]''' is an | + | '''[[Logical equality]]''' is an operation on two logical values, typically the values of two propositions, that produces a value of ''true'' if and only if both operands are false or both operands are true. |
− | The truth table of | + | The truth table of <math>p ~\operatorname{EQ}~ q,</math> also written <math>p = q,\!</math> <math>p \Leftrightarrow q,\!</math> or <math>p \equiv q,\!</math> appears below: |
<br> | <br> | ||
− | {| align="center" border="1" cellpadding="8" cellspacing="0" style=" | + | {| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:45%" |
− | |+ | + | |+ style="height:30px" | <math>\text{Logical Equality}\!</math> |
− | |- style="background:# | + | |- style="height:40px; background:#f0f0ff" |
− | + | | style="width:33%" | <math>p\!</math> | |
− | + | | style="width:33%" | <math>q\!</math> | |
− | + | | style="width:33%" | <math>p = q\!</math> | |
|- | |- | ||
− | | F || F || T | + | | <math>\operatorname{F}</math> || <math>\operatorname{F}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | F || T || F | + | | <math>\operatorname{F}</math> || <math>\operatorname{T}</math> || <math>\operatorname{F}</math> |
|- | |- | ||
− | | T || F || F | + | | <math>\operatorname{T}</math> || <math>\operatorname{F}</math> || <math>\operatorname{F}</math> |
|- | |- | ||
− | | T || T || T | + | | <math>\operatorname{T}</math> || <math>\operatorname{T}</math> || <math>\operatorname{T}</math> |
|} | |} | ||
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==Exclusive disjunction== | ==Exclusive disjunction== | ||
− | '''[[Exclusive disjunction]]''', also known as '''logical inequality''' or '''symmetric difference''', is an | + | '''[[Exclusive disjunction]]''', also known as '''logical inequality''' or '''symmetric difference''', is an operation on two logical values, typically the values of two propositions, that produces a value of ''true'' just in case exactly one of its operands is true. |
− | The truth table of | + | The truth table of <math>p ~\operatorname{XOR}~ q,</math> also written <math>p + q\!</math> or <math>p \ne q,\!</math> appears below: |
<br> | <br> | ||
− | {| align="center" border="1" cellpadding="8" cellspacing="0" style=" | + | {| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:45%" |
− | |+ | + | |+ style="height:30px" | <math>\text{Exclusive Disjunction}\!</math> |
− | |- style="background:# | + | |- style="height:40px; background:#f0f0ff" |
− | + | | style="width:33%" | <math>p\!</math> | |
− | + | | style="width:33%" | <math>q\!</math> | |
− | + | | style="width:33%" | <math>p ~\operatorname{XOR}~ q</math> | |
|- | |- | ||
− | | F || F || F | + | | <math>\operatorname{F}</math> || <math>\operatorname{F}</math> || <math>\operatorname{F}</math> |
|- | |- | ||
− | | F || T || T | + | | <math>\operatorname{F}</math> || <math>\operatorname{T}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | T || F || T | + | | <math>\operatorname{T}</math> || <math>\operatorname{F}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | T || T || F | + | | <math>\operatorname{T}</math> || <math>\operatorname{T}</math> || <math>\operatorname{F}</math> |
|} | |} | ||
<br> | <br> | ||
− | The following equivalents | + | The following equivalents may then be deduced: |
− | + | {| align="center" cellspacing="10" width="90%" | |
− | p + q & = & (p \land \lnot q) & \lor & (\lnot p \land q) | + | | |
− | \\ | + | <math>\begin{matrix} |
− | & = & (p \lor q) & \land & (\lnot p \lor \lnot q) | + | p + q & = & (p \land \lnot q) & \lor & (\lnot p \land q) |
− | \\ | + | \\[6pt] |
+ | & = & (p \lor q) & \land & (\lnot p \lor \lnot q) | ||
+ | \\[6pt] | ||
& = & (p \lor q) & \land & \lnot (p \land q) | & = & (p \lor q) & \land & \lnot (p \land q) | ||
\end{matrix}</math> | \end{matrix}</math> | ||
+ | |} | ||
==Logical implication== | ==Logical implication== | ||
− | The '''[[logical implication]]''' and the ''' | + | The '''[[logical implication]]''' relation and the '''material conditional''' function are both associated with an operation on two logical values, typically the values of two propositions, that produces a value of ''false'' if and only if the first operand is true and the second operand is false. |
− | The truth table associated with the material conditional | + | The truth table associated with the material conditional <math>\text{if}~ p ~\text{then}~ q,\!</math> symbolized <math>p \rightarrow q,\!</math> and the logical implication <math>p ~\text{implies}~ q,\!</math> symbolized <math>p \Rightarrow q,\!</math> appears below: |
<br> | <br> | ||
− | {| align="center" border="1" cellpadding="8" cellspacing="0" style=" | + | {| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:45%" |
− | |+ | + | |+ style="height:30px" | <math>\text{Logical Implication}\!</math> |
− | |- style="background:# | + | |- style="height:40px; background:#f0f0ff" |
− | + | | style="width:33%" | <math>p\!</math> | |
− | + | | style="width:33%" | <math>q\!</math> | |
− | + | | style="width:33%" | <math>p \Rightarrow q\!</math> | |
|- | |- | ||
− | | F || F || T | + | | <math>\operatorname{F}</math> || <math>\operatorname{F}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | F || T || T | + | | <math>\operatorname{F}</math> || <math>\operatorname{T}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | T || F || F | + | | <math>\operatorname{T}</math> || <math>\operatorname{F}</math> || <math>\operatorname{F}</math> |
|- | |- | ||
− | | T || T || T | + | | <math>\operatorname{T}</math> || <math>\operatorname{T}</math> || <math>\operatorname{T}</math> |
|} | |} | ||
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==Logical NAND== | ==Logical NAND== | ||
− | The '''[[logical NAND]]''' is | + | The '''[[logical NAND]]''' is an operation on two logical values, typically the values of two propositions, that produces a value of ''false'' if and only if both of its operands are true. In other words, it produces a value of ''true'' if and only if at least one of its operands is false. |
− | The truth table of | + | The truth table of <math>p ~\operatorname{NAND}~ q,</math> also written <math>p \stackrel{\circ}{\curlywedge} q\!</math> or <math>p \barwedge q,\!</math> appears below: |
<br> | <br> | ||
− | {| align="center" border="1" cellpadding="8" cellspacing="0" style=" | + | {| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:45%" |
− | |+ | + | |+ style="height:30px" | <math>\text{Logical NAND}\!</math> |
− | |- style="background:# | + | |- style="height:40px; background:#f0f0ff" |
− | + | | style="width:33%" | <math>p\!</math> | |
− | + | | style="width:33%" | <math>q\!</math> | |
− | + | | style="width:33%" | <math>p \stackrel{\circ}{\curlywedge} q\!</math> | |
|- | |- | ||
− | | F || F || T | + | | <math>\operatorname{F}</math> || <math>\operatorname{F}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | F || T || T | + | | <math>\operatorname{F}</math> || <math>\operatorname{T}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | T || F || T | + | | <math>\operatorname{T}</math> || <math>\operatorname{F}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | T || T || F | + | | <math>\operatorname{T}</math> || <math>\operatorname{T}</math> || <math>\operatorname{F}</math> |
|} | |} | ||
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==Logical NNOR== | ==Logical NNOR== | ||
− | The '''[[logical NNOR]]''' is | + | The '''[[logical NNOR]]''' (“Neither Nor”) is an operation on two logical values, typically the values of two propositions, that produces a value of ''true'' if and only if both of its operands are false. In other words, it produces a value of ''false'' if and only if at least one of its operands is true. |
− | The truth table of | + | The truth table of <math>p ~\operatorname{NNOR}~ q,</math> also written <math>p \curlywedge q,\!</math> appears below: |
<br> | <br> | ||
− | {| align="center" border="1" cellpadding="8" cellspacing="0" style=" | + | {| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:45%" |
− | |+ | + | |+ style="height:30px" | <math>\text{Logical NNOR}\!</math> |
− | |- style="background:# | + | |- style="height:40px; background:#f0f0ff" |
− | + | | style="width:33%" | <math>p\!</math> | |
− | + | | style="width:33%" | <math>q\!</math> | |
− | + | | style="width:33%" | <math>p \curlywedge q\!</math> | |
|- | |- | ||
− | | F || F || T | + | | <math>\operatorname{F}</math> || <math>\operatorname{F}</math> || <math>\operatorname{T}</math> |
|- | |- | ||
− | | F || T || F | + | | <math>\operatorname{F}</math> || <math>\operatorname{T}</math> || <math>\operatorname{F}</math> |
|- | |- | ||
− | | T || F || F | + | | <math>\operatorname{T}</math> || <math>\operatorname{F}</math> || <math>\operatorname{F}</math> |
|- | |- | ||
− | | T || T || F | + | | <math>\operatorname{T}</math> || <math>\operatorname{T}</math> || <math>\operatorname{F}</math> |
|} | |} | ||
<br> | <br> | ||
− | ==Logical operators== | + | ==Translations== |
+ | |||
+ | * [http://zh.wikipedia.org/wiki/%E7%9C%9F%E5%80%BC%E8%A1%A8 中文 : 真值表] | ||
+ | |||
+ | ==Syllabus== | ||
+ | |||
+ | ===Focal nodes=== | ||
+ | |||
+ | * [[Inquiry Live]] | ||
+ | * [[Logic Live]] | ||
+ | |||
+ | ===Peer nodes=== | ||
+ | |||
+ | * [http://intersci.ss.uci.edu/wiki/index.php/Truth_table Truth Table @ InterSciWiki] | ||
+ | * [http://mywikibiz.com/Truth_table Truth Table @ MyWikiBiz] | ||
+ | * [http://ref.subwiki.org/wiki/Truth_table Truth Table @ Subject Wikis] | ||
+ | * [http://en.wikiversity.org/wiki/Truth_table Truth Table @ Wikiversity] | ||
+ | * [http://beta.wikiversity.org/wiki/Truth_table Truth Table @ Wikiversity Beta] | ||
+ | |||
+ | ===Logical operators=== | ||
{{col-begin}} | {{col-begin}} | ||
Line 251: | Line 280: | ||
{{col-end}} | {{col-end}} | ||
− | ==Related topics== | + | ===Related topics=== |
{{col-begin}} | {{col-begin}} | ||
{{col-break}} | {{col-break}} | ||
* [[Ampheck]] | * [[Ampheck]] | ||
− | |||
* [[Boolean domain]] | * [[Boolean domain]] | ||
* [[Boolean function]] | * [[Boolean function]] | ||
+ | * [[Boolean-valued function]] | ||
+ | * [[Differential logic]] | ||
{{col-break}} | {{col-break}} | ||
− | |||
− | |||
− | |||
* [[Logical graph]] | * [[Logical graph]] | ||
+ | * [[Minimal negation operator]] | ||
+ | * [[Multigrade operator]] | ||
+ | * [[Parametric operator]] | ||
+ | * [[Peirce's law]] | ||
{{col-break}} | {{col-break}} | ||
− | |||
− | |||
* [[Propositional calculus]] | * [[Propositional calculus]] | ||
+ | * [[Sole sufficient operator]] | ||
+ | * [[Truth table]] | ||
+ | * [[Universe of discourse]] | ||
* [[Zeroth order logic]] | * [[Zeroth order logic]] | ||
+ | {{col-end}} | ||
+ | |||
+ | ===Relational concepts=== | ||
+ | |||
+ | {{col-begin}} | ||
+ | {{col-break}} | ||
+ | * [[Continuous predicate]] | ||
+ | * [[Hypostatic abstraction]] | ||
+ | * [[Logic of relatives]] | ||
+ | * [[Logical matrix]] | ||
+ | {{col-break}} | ||
+ | * [[Relation (mathematics)|Relation]] | ||
+ | * [[Relation composition]] | ||
+ | * [[Relation construction]] | ||
+ | * [[Relation reduction]] | ||
+ | {{col-break}} | ||
+ | * [[Relation theory]] | ||
+ | * [[Relative term]] | ||
+ | * [[Sign relation]] | ||
+ | * [[Triadic relation]] | ||
+ | {{col-end}} | ||
+ | |||
+ | ===Information, Inquiry=== | ||
+ | |||
+ | {{col-begin}} | ||
+ | {{col-break}} | ||
+ | * [[Inquiry]] | ||
+ | * [[Dynamics of inquiry]] | ||
+ | {{col-break}} | ||
+ | * [[Semeiotic]] | ||
+ | * [[Logic of information]] | ||
+ | {{col-break}} | ||
+ | * [[Descriptive science]] | ||
+ | * [[Normative science]] | ||
+ | {{col-break}} | ||
+ | * [[Pragmatic maxim]] | ||
+ | * [[Truth theory]] | ||
+ | {{col-end}} | ||
+ | |||
+ | ===Related articles=== | ||
+ | |||
+ | {{col-begin}} | ||
+ | {{col-break}} | ||
+ | * [http://intersci.ss.uci.edu/wiki/index.php/Cactus_Language Cactus Language] | ||
+ | * [http://intersci.ss.uci.edu/wiki/index.php/Futures_Of_Logical_Graphs Futures Of Logical Graphs] | ||
+ | * [http://intersci.ss.uci.edu/wiki/index.php/Propositional_Equation_Reasoning_Systems Propositional Equation Reasoning Systems] | ||
+ | {{col-break}} | ||
+ | * [http://intersci.ss.uci.edu/wiki/index.php/Differential_Logic_:_Introduction Differential Logic : Introduction] | ||
+ | * [http://intersci.ss.uci.edu/wiki/index.php/Differential_Propositional_Calculus Differential Propositional Calculus] | ||
+ | * [http://intersci.ss.uci.edu/wiki/index.php/Differential_Logic_and_Dynamic_Systems_2.0 Differential Logic and Dynamic Systems] | ||
+ | {{col-break}} | ||
+ | * [http://intersci.ss.uci.edu/wiki/index.php/Prospects_for_Inquiry_Driven_Systems Prospects for Inquiry Driven Systems] | ||
+ | * [http://intersci.ss.uci.edu/wiki/index.php/Introduction_to_Inquiry_Driven_Systems Introduction to Inquiry Driven Systems] | ||
+ | * [http://intersci.ss.uci.edu/wiki/index.php/Inquiry_Driven_Systems Inquiry Driven Systems : Inquiry Into Inquiry] | ||
{{col-end}} | {{col-end}} | ||
==Document history== | ==Document history== | ||
− | + | Portions of the above article were adapted from the following sources under the [[GNU Free Documentation License]], under other applicable licenses, or by permission of the copyright holders. | |
+ | |||
+ | * [http://intersci.ss.uci.edu/wiki/index.php/Truth_table Truth Table], [http://intersci.ss.uci.edu/ InterSciWiki] | ||
+ | * [http://mywikibiz.com/Truth_table Truth Table], [http://mywikibiz.com/ MyWikiBiz] | ||
+ | * [http://semanticweb.org/wiki/Truth_table Truth Table], [http://semanticweb.org/ SemanticWeb] | ||
+ | * [http://wikinfo.org/w/index.php/Truth_table Truth Table], [http://wikinfo.org/w/ Wikinfo] | ||
+ | * [http://en.wikiversity.org/wiki/Truth_table Truth Table], [http://en.wikiversity.org/ Wikiversity] | ||
+ | * [http://beta.wikiversity.org/wiki/Truth_table Truth Table], [http://beta.wikiversity.org/ Wikiversity Beta] | ||
+ | * [http://en.wikipedia.org/w/index.php?title=Truth_table&oldid=77110085 Truth Table], [http://en.wikipedia.org/ Wikipedia] | ||
+ | [[Category:Inquiry]] | ||
+ | [[Category:Open Educational Resource]] | ||
+ | [[Category:Peer Educational Resource]] | ||
+ | [[Category:Charles Sanders Peirce]] | ||
[[Category:Combinatorics]] | [[Category:Combinatorics]] | ||
[[Category:Computer Science]] | [[Category:Computer Science]] |
Latest revision as of 03:25, 30 October 2015
☞ This page belongs to resource collections on Logic and Inquiry.
A truth table is a tabular array that illustrates the computation of a logical function, that is, a function of the form \(f : \mathbb{A}^k \to \mathbb{A},\) where \(k\!\) is a non-negative integer and \(\mathbb{A}\) is the domain of logical values \(\{ \operatorname{false}, \operatorname{true} \}.\) The names of the logical values, or truth values, are commonly abbreviated in accord with the equations \(\operatorname{F} = \operatorname{false}\) and \(\operatorname{T} = \operatorname{true}.\)
In many applications it is usual to represent a truth function by a boolean function, that is, a function of the form \(f : \mathbb{B}^k \to \mathbb{B},\) where \(k\!\) is a non-negative integer and \(\mathbb{B}\) is the boolean domain \(\{ 0, 1 \}.\!\) In most applications \(\operatorname{false}\) is represented by \(0\!\) and \(\operatorname{true}\) is represented by \(1\!\) but the opposite representation is also possible, depending on the overall representation of truth functions as boolean functions. The remainder of this article assumes the usual representation, taking the equations \(\operatorname{F} = 0\) and \(\operatorname{T} = 1\) for granted.
Logical negation
Logical negation is an operation on one logical value, typically the value of a proposition, that produces a value of true when its operand is false and a value of false when its operand is true.
The truth table of \(\operatorname{NOT}~ p,\) also written \(\lnot p,\!\) appears below:
\(p\!\) | \(\lnot p\!\) |
\(\operatorname{F}\) | \(\operatorname{T}\) |
\(\operatorname{T}\) | \(\operatorname{F}\) |
The negation of a proposition \(p\!\) may be found notated in various ways in various contexts of application, often merely for typographical convenience. Among these variants are the following:
\(\text{Notation}\!\) | \(\text{Vocalization}\!\) |
\(\bar{p}\!\) | \(p\!\) bar |
\(\tilde{p}\!\) | \(p\!\) tilde |
\(p'\!\) | \(p\!\) prime \(p\!\) complement |
\(!p\!\) | bang \(p\!\) |
Logical conjunction
Logical conjunction is an operation on two logical values, typically the values of two propositions, that produces a value of true if and only if both of its operands are true.
The truth table of \(p ~\operatorname{AND}~ q,\) also written \(p \land q\!\) or \(p \cdot q,\!\) appears below:
\(p\!\) | \(q\!\) | \(p \land q\) |
\(\operatorname{F}\) | \(\operatorname{F}\) | \(\operatorname{F}\) |
\(\operatorname{F}\) | \(\operatorname{T}\) | \(\operatorname{F}\) |
\(\operatorname{T}\) | \(\operatorname{F}\) | \(\operatorname{F}\) |
\(\operatorname{T}\) | \(\operatorname{T}\) | \(\operatorname{T}\) |
Logical disjunction
Logical disjunction, also called logical alternation, is an operation on two logical values, typically the values of two propositions, that produces a value of false if and only if both of its operands are false.
The truth table of \(p ~\operatorname{OR}~ q,\) also written \(p \lor q,\!\) appears below:
\(p\!\) | \(q\!\) | \(p \lor q\) |
\(\operatorname{F}\) | \(\operatorname{F}\) | \(\operatorname{F}\) |
\(\operatorname{F}\) | \(\operatorname{T}\) | \(\operatorname{T}\) |
\(\operatorname{T}\) | \(\operatorname{F}\) | \(\operatorname{T}\) |
\(\operatorname{T}\) | \(\operatorname{T}\) | \(\operatorname{T}\) |
Logical equality
Logical equality is an operation on two logical values, typically the values of two propositions, that produces a value of true if and only if both operands are false or both operands are true.
The truth table of \(p ~\operatorname{EQ}~ q,\) also written \(p = q,\!\) \(p \Leftrightarrow q,\!\) or \(p \equiv q,\!\) appears below:
\(p\!\) | \(q\!\) | \(p = q\!\) |
\(\operatorname{F}\) | \(\operatorname{F}\) | \(\operatorname{T}\) |
\(\operatorname{F}\) | \(\operatorname{T}\) | \(\operatorname{F}\) |
\(\operatorname{T}\) | \(\operatorname{F}\) | \(\operatorname{F}\) |
\(\operatorname{T}\) | \(\operatorname{T}\) | \(\operatorname{T}\) |
Exclusive disjunction
Exclusive disjunction, also known as logical inequality or symmetric difference, is an operation on two logical values, typically the values of two propositions, that produces a value of true just in case exactly one of its operands is true.
The truth table of \(p ~\operatorname{XOR}~ q,\) also written \(p + q\!\) or \(p \ne q,\!\) appears below:
\(p\!\) | \(q\!\) | \(p ~\operatorname{XOR}~ q\) |
\(\operatorname{F}\) | \(\operatorname{F}\) | \(\operatorname{F}\) |
\(\operatorname{F}\) | \(\operatorname{T}\) | \(\operatorname{T}\) |
\(\operatorname{T}\) | \(\operatorname{F}\) | \(\operatorname{T}\) |
\(\operatorname{T}\) | \(\operatorname{T}\) | \(\operatorname{F}\) |
The following equivalents may then be deduced:
\(\begin{matrix} p + q & = & (p \land \lnot q) & \lor & (\lnot p \land q) \\[6pt] & = & (p \lor q) & \land & (\lnot p \lor \lnot q) \\[6pt] & = & (p \lor q) & \land & \lnot (p \land q) \end{matrix}\) |
Logical implication
The logical implication relation and the material conditional function are both associated with an operation on two logical values, typically the values of two propositions, that produces a value of false if and only if the first operand is true and the second operand is false.
The truth table associated with the material conditional \(\text{if}~ p ~\text{then}~ q,\!\) symbolized \(p \rightarrow q,\!\) and the logical implication \(p ~\text{implies}~ q,\!\) symbolized \(p \Rightarrow q,\!\) appears below:
\(p\!\) | \(q\!\) | \(p \Rightarrow q\!\) |
\(\operatorname{F}\) | \(\operatorname{F}\) | \(\operatorname{T}\) |
\(\operatorname{F}\) | \(\operatorname{T}\) | \(\operatorname{T}\) |
\(\operatorname{T}\) | \(\operatorname{F}\) | \(\operatorname{F}\) |
\(\operatorname{T}\) | \(\operatorname{T}\) | \(\operatorname{T}\) |
Logical NAND
The logical NAND is an operation on two logical values, typically the values of two propositions, that produces a value of false if and only if both of its operands are true. In other words, it produces a value of true if and only if at least one of its operands is false.
The truth table of \(p ~\operatorname{NAND}~ q,\) also written \(p \stackrel{\circ}{\curlywedge} q\!\) or \(p \barwedge q,\!\) appears below:
\(p\!\) | \(q\!\) | \(p \stackrel{\circ}{\curlywedge} q\!\) |
\(\operatorname{F}\) | \(\operatorname{F}\) | \(\operatorname{T}\) |
\(\operatorname{F}\) | \(\operatorname{T}\) | \(\operatorname{T}\) |
\(\operatorname{T}\) | \(\operatorname{F}\) | \(\operatorname{T}\) |
\(\operatorname{T}\) | \(\operatorname{T}\) | \(\operatorname{F}\) |
Logical NNOR
The logical NNOR (“Neither Nor”) is an operation on two logical values, typically the values of two propositions, that produces a value of true if and only if both of its operands are false. In other words, it produces a value of false if and only if at least one of its operands is true.
The truth table of \(p ~\operatorname{NNOR}~ q,\) also written \(p \curlywedge q,\!\) appears below:
\(p\!\) | \(q\!\) | \(p \curlywedge q\!\) |
\(\operatorname{F}\) | \(\operatorname{F}\) | \(\operatorname{T}\) |
\(\operatorname{F}\) | \(\operatorname{T}\) | \(\operatorname{F}\) |
\(\operatorname{T}\) | \(\operatorname{F}\) | \(\operatorname{F}\) |
\(\operatorname{T}\) | \(\operatorname{T}\) | \(\operatorname{F}\) |
Translations
Syllabus
Focal nodes
Peer nodes
- Truth Table @ InterSciWiki
- Truth Table @ MyWikiBiz
- Truth Table @ Subject Wikis
- Truth Table @ Wikiversity
- Truth Table @ Wikiversity Beta
Logical operators
Template:Col-breakTemplate:Col-breakTemplate:Col-endRelated topics
- Propositional calculus
- Sole sufficient operator
- Truth table
- Universe of discourse
- Zeroth order logic
Relational concepts
Information, Inquiry
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Document history
Portions of the above article were adapted from the following sources under the GNU Free Documentation License, under other applicable licenses, or by permission of the copyright holders.
- Truth Table, InterSciWiki
- Truth Table, MyWikiBiz
- Truth Table, SemanticWeb
- Truth Table, Wikinfo
- Truth Table, Wikiversity
- Truth Table, Wikiversity Beta
- Truth Table, Wikipedia