Re: just doesn't work

*To*: mathgroup at smc.vnet.net*Subject*: [mg25385] Re: [mg25346] just doesn't work*From*: "Rosa Ma. Seco" <ceie at prodigy.net.mx>*Date*: Fri, 29 Sep 2000 01:06:16 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Question 1. Try to separate the notion of a text editor from a mathematical system such as Mathematica. The function ReplaceAll is defined by "expr /. rules applies a rule or list of rules in an attempt to transform each subpart of an expression expr." If you look at your expression in FullForm In[57]:= FullForm[(4 a^3 b c K Pi Ro)/(15 r^3)] Out[57]//FullForm= Times[Rational[4,15],Power[a,3],b,c,K,Pi,Power[r,-3],Ro] you'll see that no sub part of it is ever going to be substituted by m. However, in the text editor context simply use Find and Replace. Question 2. Use Simplify: In[1]:= Simplify[a^2 b c + a b c] Out[1]= a (1+a) b c Tomas Garza Mexico City Borut L [mailto:justmyname at email.si] wrote: > I am writing a paper in Mathematica 4.0, and I found it to be > very powerful > text editor. However, I encountered some deadly problems, which I cannot > solve. Thanks for any help! > > 1. How can I replace a symbol m with (4 a b c Pi Ro)/3 in expr > > (4 a^3 b c K Pi Ro)/(15 r^3) > > expr/.(4 a b c Pi Ro)/3 -> m > just doesn't work > > > 2. How Can I 'bring out' a defined part from a sum of two terms. > > e.g. > > Bo[a^2 b c + a b c,a b c] - (would produce) - > a b c (a+1) > > Collect[expr,{a,b,c}] > just doesn't work.

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**Re: Integrate doesn't yield what I expect**

**Re: just doesn't work**

**winding number**