Re: Need a functional process for this.

*To*: mathgroup at smc.vnet.net*Subject*: [mg55626] Re: Need a functional process for this.*From*: koopman at sfu.ca (Ray Koopman)*Date*: Thu, 31 Mar 2005 01:25:02 -0500 (EST)*References*: <d2dpdm$lsd$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Steve Gray <stevebg at adelphia.net> wrote in message news:<d2dpdm$lsd$1 at smc.vnet.net>... > I have two lists, aa and bb. aa has the general form {2,5,7,9,11,...} > (or{{2},{5},{7},{9},{11},?}}), and bb has the general form > {{6,4},{9,2},{5,6},{3,8},?}. If either > the first or second element in any sublist (pair of integers) of bb > matches any element in aa, I > want to delete that sublist from bb. In the above example, > neither member of {6,4} or {3,8} belongs > to aa, while at least one element of {9,2} and {5,6} belongs to aa, > so bb becomes {{6,4},{3,8}}. If > aa had only one element, for example 7, I could do > bb=Delete[bb,Position[bb,{x_,7}|{7,y_}]], but I > don't know how to do it for several values instead of just "7" > without using a procedural loop. > What is a good functional way to do this? > Thank you for any tips. > > Steve Gray In[1]:= aa = {2,5,7,9,11}; bb = {{6,4},{9,2},{5,6},{3,8}}; DeleteCases[bb,{b1_,b2_}/;MemberQ[aa,b1]||MemberQ[aa,b2]] Out[2]= {{6,4},{3,8}}