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| ==Exclusive disjunction== | | ==Exclusive disjunction== |
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− | ''[[Exclusive disjunction]]'', also known as ''logical inequality'' or ''symmetric difference'', is an [[logical operation|operation]] on two [[logical value]]s, typically the values of two [[proposition]]s, that produces a value of ''true'' just in case exactly one of its operands is true. | + | '''[[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. |
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− | The truth table of '''p XOR q''' (also written as '''p + q''', '''p ⊕ q''', or '''p ≠ q''') is as follows: | + | The truth table of <math>p ~\operatorname{XOR}~ q,</math> also written <math>p + q\!</math> or <math>p \ne q,\!</math> appears below: |
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| <br> | | <br> |
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− | {| align="center" border="1" cellpadding="8" cellspacing="0" style="background:#f8f8ff; font-weight:bold; text-align:center; width:45%" | + | {| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:45%" |
− | |+ '''Exclusive Disjunction''' | + | |+ style="height:30px" | <math>\text{Exclusive Disjunction}\!</math> |
− | |- style="background:#e6e6ff" | + | |- style="height:40px; background:#f0f0ff" |
− | ! style="width:15%" | p
| + | | style="width:33%" | <math>p\!</math> |
− | ! style="width:15%" | q
| + | | style="width:33%" | <math>q\!</math> |
− | ! style="width:15%" | p XOR q
| + | | 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> |
| |} | | |} |
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| <br> | | <br> |
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− | The following equivalents can then be deduced: | + | The following equivalents may then be deduced: |
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− | : <math>\begin{matrix}
| + | {| 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> |
| + | |} |
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| ==Logical implication== | | ==Logical implication== |