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Re: replace one rule in a list of rules

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  • Subject: [mg125553] Re: replace one rule in a list of rules
  • From: Murray Eisenberg <murray at>
  • Date: Sun, 18 Mar 2012 02:46:42 -0500 (EST)
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  • Reply-to: murray at

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

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.:


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
Mathematics & Statistics Dept.
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University of Massachusetts                413 545-2859 (W)
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