Re: Help with concatenating a list with &&
- To: mathgroup at smc.vnet.net
- Subject: [mg102193] Re: [mg102153] Help with concatenating a list with &&
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Sat, 1 Aug 2009 03:58:07 -0400 (EDT)
- Organization: Mathematics & Statistics, Univ. of Mass./Amherst
- References: <200907310952.FAA19208@smc.vnet.net>
- Reply-to: murray at math.umass.edu
And @@ {ex1, ex2, ex3, ex4} ex1&&ex2&&ex3&&ex4 In general, beware of using "special input forms" (such as && instead of the actual function And) in combination with functional constructs (such as Apply). janey wrote: > Can anyone help me make better use of mathematica's built in commands? > > My problem is to take the list of expressions ls: > > ls={ex1, ex2, ex3, ex4} > > and connect them to obtain > > ex1 && ex2 && ex3 && ex4 > > > I thought I should be able to use > > && @@ ls > > or equivalently Apply[&&, ls] > > However this fails. I ended up using the very awkward > > conditions = ls[[1]] && ls[[2]] > Do[conds = conds && ls[[i]], {i, 3, Length[ls]}] > > which works but feels like just bludgeoning the problem > > Does anyone know of a more elegant way to work this? > > Thanks, > Jane. > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305