Problem with Patterns and Integrate

*To*: mathgroup at smc.vnet.net*Subject*: [mg123234] Problem with Patterns and Integrate*From*: Jack McInerney <ejmcinerney at gmail.com>*Date*: Mon, 28 Nov 2011 05:53:30 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

There is something about using patterns that I don't understand, and am hoping someone can shed some light. Here is an example of my problem. Say I have a function f[x] and I take the derivative of it. I can then integrate it and get f[x] back: In[167]:= expr = D[ f[x], x ] Out[167]= f=E2=80=B2[x] In[168]:= Integrate[expr, x] Out[168]= f[x] If I use a ReplaceAll and a pattern to do the integration, the Integrate function treats f'[x] as a constant and returns the wrong answer: In[169]:= expr /. func_ -> Integrate[func,x] Out[169]= x f=E2=80=B2[x] Any thoughts as to what I am doing wrong? Jack

**Follow-Ups**:**Re: Problem with Patterns and Integrate***From:*Barrie Stokes <Barrie.Stokes@newcastle.edu.au>

**Re: Problem with Patterns and Integrate***From:*Bob Hanlon <hanlonr357@gmail.com>