Basic Examples (2) 

Find the repeated term in the expression (a+b+c)³+(a+b+c)²:

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Reconstruct the original expression from the decomposed form:

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Options (6) 

Finding many small common subexpressions may not be helpful:

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Find only the largest with "MinLeafCount":

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You can control the prefix used for subexpressions by providing a string:

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You can also control the names used for subexpressions by providing a list of variable names:

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Or by providing a generating function:

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The "VariableNames" option takes the subexpression as an argument:

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Applications (1) 

Remove the discriminant from the quadratic solution equations:

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Properties and Relations (1) 

Reconstruct the original expression from the decomposed form by applying ReplaceRepeated:

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Possible Issues (2) 

The FullForm of subexpressions must match; in this case, no match is found:

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This is because the outermost Plus has four arguments and not just the a, b and c:

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If the input expression contains elements with HoldAll, HoldRest or HoldFirst, the contents will evaluate during the search:

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Neat Examples (3) 

Simplify the third-degree polynomial solution:

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And the fourth-degree polynomial solution:

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Construct meaningful variable names based on their content:

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