Re: Intersection problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg125989] Re: Intersection problem*From*: Alexei Boulbitch <Alexei.Boulbitch at iee.lu>*Date*: Wed, 11 Apr 2012 18:20:29 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

I need to select out the elements of the first list whose first elements are contained in the second list. For example first list: {{a,x},{b,y},{c,z}} second list: {b,c,d} result: {{b,y},{c,z}} Is there a quick way to do this? Intersection, maybe somehow? Try this: Select[{{a, x}, {b, y}, {c, z}}, MemberQ[{b, c, d}, #[[1]]] &] {{b, y}, {c, z}} Have fun. Alexei BOULBITCH, Dr., habil. IEE S.A. ZAE Weiergewan, 11, rue Edmond Reuter, L-5326 Contern, LUXEMBOURG Office phone : +352-2454-2566 Office fax: +352-2454-3566 mobile phone: +49 151 52 40 66 44 e-mail: alexei.boulbitch at iee.lu