Re: rule based program for "Deleting repeated members of a list."
- To: mathgroup at smc.vnet.net
- Subject: [mg82066] Re: rule based program for "Deleting repeated members of a list."
- From: Szabolcs Horvát <szhorvat at gmail.com>
- Date: Thu, 11 Oct 2007 00:17:52 -0400 (EDT)
- References: <fe7j44$qga$1@smc.vnet.net> <fea9ju$k4g$1@smc.vnet.net> <fei2kq$qa4$1@smc.vnet.net>
Jean-Marc Gulliet wrote:
> I was wandering why you used b and d as pattern name with a condition on
> them rather than b and c, but I realized that when using c as pattern
> name in place of d the replacement fails.
>
> In[1]:= s = {a, b, c, c, d, e, e, f, g, g, g, h, a, b};
Hi,
You probably noticed this by now, but on the following line there should
be {a,b,d} instead of {a,b,d}
> s //. {a___, b_, c_, d___} :> {a, b, c} /; b == c
---------------------------------------^
s //. {a___, b_, c_, d___} :> {a, b, d} /. b === c
> s //. {a___, b_, d_, e___} :> {a, b, e} /; b == d
>
> Out[2]= {a, b, c, c}
>
> Out[3]= {a, b, c, d, e, f, g, h, a, b}
>
> Does anyone know why?
>
--
Szabolcs