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==Logical negation==
 
==Logical negation==
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''[[Logical negation]]'' is an [[logical operation|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.
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'''[[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.
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The truth table of '''NOT p''' (also written as '''~p''' or '''¬p''') is as follows:
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The [[truth table]] of <math>\operatorname{NOT}~ p,</math> also written <math>\lnot p,\!</math> appears below:
    
<br>
 
<br>
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{| align="center" border="1" cellpadding="8" cellspacing="0" style="background:#f8f8ff; font-weight:bold; text-align:center; width:40%"
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{| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:45%"
|+ '''Logical Negation'''
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|+ style="height:30px" | <math>\text{Logical Negation}\!</math>
|- style="background:#e6e6ff"
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|- style="height:40px; background:#f0f0ff"
! style="width:20%" | p
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| style="width:50%" | <math>p\!</math>
! style="width:20%" | &not;p
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| style="width:50%" | <math>\lnot p\!</math>
 
|-
 
|-
| F || T
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| <math>\operatorname{F}</math> || <math>\operatorname{T}</math>
 
|-
 
|-
| T || F
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| <math>\operatorname{T}</math> || <math>\operatorname{F}</math>
 
|}
 
|}
    
<br>
 
<br>
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The logical negation of a proposition '''p''' is notated in different ways in various contexts of discussion and fields of application.  Among these variants are the following:
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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>
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{| align="center" border="1" cellpadding="8" cellspacing="0" style="background:#f8f8ff; width:40%"
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{| align="center" border="1" cellpadding="8" cellspacing="0" width="45%"
|+ '''Variant Notations'''
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|+ style="height:30px" | <math>\text{Variant Notations}\!</math>
|- style="background:#e6e6ff"
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|- style="height:40px; background:#f0f0ff"
! style="text-align:center" | Notation
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| width="50%" align="center" | <math>\text{Notation}\!</math>
! Vocalization
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| width="50%" | <math>\text{Vocalization}\!</math>
 
|-
 
|-
| style="text-align:center" | <math>\bar{p}</math>
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| align="center" | <math>\bar{p}\!</math>
| bar ''p''
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| <math>p\!</math> bar
 
|-
 
|-
| style="text-align:center" | <math>p'\!</math>
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| align="center" | <math>\tilde{p}\!</math>
| ''p'' prime,<p> ''p'' complement
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| <math>p\!</math> tilde
 
|-
 
|-
| style="text-align:center" | <math>!p\!</math>
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| align="center" | <math>p'\!</math>
| bang ''p''
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| <math>p\!</math> prime<br> <math>p\!</math> complement
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|-
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| align="center" | <math>!p\!</math>
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| bang <math>p\!</math>
 
|}
 
|}
  
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