Re: Simplifying constants...bug?

*To*: mathgroup at smc.vnet.net*Subject*: [mg18559] Re: [mg18489] Simplifying constants...bug?*From*: calvitti at boes.ces.cwru.edu*Date*: Sat, 10 Jul 1999 02:18:50 -0400*Organization*: Case Western Reserve University*References*: <7m3l22$shp@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

here's some intersting behavior in 3.0: (a + c*d)/(b + c*d) //. c*d -> -z gives (as expected): (a - z)/(b - z) yet (a + c*d)/(c*d) //. c*d -> -z no longer simplifes the denominator: (a+b-z)/(c*d) anyone know why? +------------------------------------------+ alan c systems and control engineering case western reserve university calvitti at alpha.ces.cwru.edu +------------------------------------------+ "Ersek, Ted R" <ErsekTR at navair.navy.mil> writes: > Morten G. Dyndgaard wrote: > ----------------------------- > I am working with some annoyingly long equations that I want to simplify > by including one set of parameters in a constant (or function) A, and > another in B and so on. > > You can easily do: > A = b+c+d+e > > but what I want to do is the reverse: > b+c+d+e = A > ----------------------------- > > This should help. > In[1]:= > expr=a+b+b1+c+c1+d+d1+e; > > > In[2]:= > expr/.a+b+c+d+e->A > > Out[2]= > A+b1+c1+d1 > > > Regards, > Ted Ersek

**Follow-Ups**:**Re: Re: Simplifying constants...bug?***From:*"Carl K.Woll" <carlw@fermi.phys.washington.edu>

**Re: Re: Simplifying constants...bug?***From:*"Wolf, Hartmut" <hwolf@debis.com>

**Re: Re: Simplifying constants...bug?***From:*"Kevin J. McCann" <kevinmccann@Home.com>