Re: replace one rule in a list of rules

*To*: mathgroup at smc.vnet.net*Subject*: [mg125553] Re: replace one rule in a list of rules*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Sun, 18 Mar 2012 02:46:42 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201203170751.CAA05105@smc.vnet.net>*Reply-to*: murray at math.umass.edu

Not sure what you mean by "repeatedly replace one of [the rules]". After all, if you have a list of rules with repeats, e.g., myrules = {a -> b, c -> d, e -> f, c -> d}; then you could get rid of the repeats by using, say, Union: simplerules = Union@myrules {a->b,c->d,e->f} So your problem really seems to be to replace _one_ of the rules. And then replace that one rule just as you'd replace anything, e.g.: simplerules/.(c->d)->(c->wow) {a->b,c->wow,e->f} Or is your problem something else? On 3/17/12 3:51 AM, Kathryn Isaac wrote: > I have a list of simple rules. I want to repeatedly replace one of > them. Is the best way to simply prepend the new rules, or is there a > "prettier" approach? > > Thanks, > Alan Isaac > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305

**References**:**replace one rule in a list of rules***From:*Kathryn Isaac <kathryn.isaac@gmail.com>