Re: How to remove external parentheses from a list

*To*: mathgroup at smc.vnet.net*Subject*: [mg131521] Re: How to remove external parentheses from a list*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Sat, 17 Aug 2013 02:06:43 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net

On 8/16/13 at 7:06 AM, sy81 at sussex.ac.uk (Samuel Mark Young) wrote: >I'm looking for an easy way to remove the external parentheses from >a list. The list contains integration variables and their >respective limits, it currently looks something like this: >{{x1,a,b},{x2,c,d},...,{xn,y,z}} >However, the Integrate (or NIntegrate function) in Mathematica wants >me to write it like this: >{x1,a,b},{x2,c,d},...,{xn,y,z} i.e. The external parentheses have >been removed >I've looked around online and seen suggestions for replacing the >curly brackets "{" with a blank space " ", or using Apply (@@) but >can't work out the correct syntax. I assume what you are doing is building a list of of integration variables and limits. If so, Sequence is the function you want. You would use it with NIntegrate as follows: NIntegrate[expressio, Sequence@@{{x1,a,b},{x2,c,d},...,{xn,y,z}}, options]