Consider the sum


I want to order this sum in such the I have the powers in ascending order


And I want the procedure to be completely general, so that i works on any polynomial of any finite order in x. I have tried Expand (I have another series, not the simple example above) and it doesn't order my series the way I want.


closed as unclear what you're asking by AccidentalFourierTransform, MarcoB, m_goldberg, Henrik Schumacher, LLlAMnYP Jul 27 '18 at 15:02

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  • 9
    $\begingroup$ don't you get that by default: expr = x^1 + x^3 + x^2 + x^4; expr? $\endgroup$ – kglr Jul 25 '18 at 15:14

One way is to define function

inverseorder[expr_] := HoldForm[expr /. Plus -> CirclePlus // Evaluate] /. CirclePlus -> Plus

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