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$\left[a\,b\,c\right]$

$\left[{\,}\right]$
 (3) 
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$\mathrm{nops}\left(\right)$

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$\left[1\,a\,3\right]$

$\left[{1}{\,}{\,}{3}\right]$
 (5) 
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$\left[1\,b\,3\right]$

$\left[{1}{\,}{3}\right]$
 (6) 
The empty symbol can be used to display unsimplified math and formulae with values substituted. Note the difference between using the empty symbol and quotes.
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$\mathrm{``}\left(2\right)\mathrm{``}\left(3\right)$

${}\left({2}\right){}{}\left({3}\right)$
 (7) 
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$\mathrm{expand}\left(\right)$

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$3\mathrm{``}\left(x\right)\+2\mathrm{``}\left(y\right)$

${3}{}{}\left({2}\right){\+}{2}{}{}\left({3}\right)$
 (11) 