While there is this question with a very similar title, it does not answer my question, which is:

I have part of an input, in my case


which Mathematica "simplifies" to


So I am wondering how to tell Mathematica to leave this expression, whether it's alone or part of a longer formula, in its previous form rather than to change it as shown here.


I should probably add I am still running version 6, hoping this is not causing the issue.

  • $\begingroup$ I can not reproduce your problem. Re[Exp[I*x]] does not automatically simplify to anything. Evaluating it leaves it unchanged. Evaluating Re[Exp[I*x]] // Simplify doesn't change it either. $\endgroup$
    – m_goldberg
    Jul 15, 2013 at 12:47
  • $\begingroup$ Maybe this is because I am still running Mathematica v6? But should it behave differently in such a way? If I evaluate Re[Exp[I*x]] in a new notebook, I get the above expression. $\endgroup$
    – Bernd
    Jul 15, 2013 at 12:51
  • $\begingroup$ i agree with @m_goldberg, but if you want to suppress on the fly simplification from Mathematica enclose it in a HoldForm expression. Is that what you're asking for? $\endgroup$
    – Stefan
    Jul 15, 2013 at 12:51
  • $\begingroup$ @Stefan, HoldForm might work but it seems be a little tricky to use in this case if I want to use the expression in a longer formula e.g. involving slots (#) where the evaluation must not be stopped. I was hoping there would be some solution of the form expression //SomeForm? $\endgroup$
    – Bernd
    Jul 15, 2013 at 12:58
  • $\begingroup$ @Bernd what about Defer@Integrate[x^# Exp[-x], {x, 0, 1}]&/@Range[2] ? $\endgroup$
    – Stefan
    Jul 15, 2013 at 13:07

1 Answer 1


In case you want Mathematica to suppress on the fly simplification and having slots (#) involved, you might consider using Defer:

Defer@Integrate[x^# Exp[-x], {x, 0, 1}]&/@Range[2] 

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