just doesn't work

*To*: mathgroup at smc.vnet.net*Subject*: [mg25346] just doesn't work*From*: "Borut L" <justmyname at email.si>*Date*: Sat, 23 Sep 2000 03:36:13 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Helo, 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. Borut, f.r.o.m. Slovenia