Re: Rule replacement doesn't work after NDSolve?

*To*: mathgroup at smc.vnet.net*Subject*: [mg124068] Re: Rule replacement doesn't work after NDSolve?*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Sat, 7 Jan 2012 05:26:03 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

On 1/6/12 at 4:18 AM, g.crlsn at gmail.com (gac) wrote: >I see that the FullForm[-2*I] is also not >Times[Complex[-2,0],Complex[0,1]]. >So this won't work either: >-2*I/.Complex[0,1]->Complex[0,-1] >to replace only I with -I, we need to use parentheses: >-2*(I/.I->-I) No, it is not necessary to use parentheses. This works: In[8]:= 2 I /. Complex[_, a_] -> -a I Out[8]= -2 I