*To*: mathgroup@smc.vnet.net*Subject*: [mg10726] Re: [Q] How to get rid of {} ???*From*: "P.J. Hinton" <paulh@wolfram.com>*Date*: Mon, 2 Feb 1998 00:44:20 -0500*Organization*: Wolfram Research, Inc.*References*: <6as8tj$f7i@smc.vnet.net>

On 30 Jan 1998, Alessandro Rossi wrote: > Hi everyone again... > I'm just curious to ask if is it possible to get rid of the {} simbols > in a plain list of this kind {a1, a2, a3, ..., an} when you want to use > the ordered sequence of a1, a2, a3, ..., an as arguments for a > function. > > e.g. > l > > > If I have the following list: > list={True, False, True} > > how can I computethe And Function of the three arguments of list: > > And[True, False, True] > > obviously > > And[list] > > doesn't work... > > It seems to me a very simple problem, but at the same time I really can > not solve it. Any samaritan willing to give me some indication to solve > this "Columbus Egg"??? And[Evaluate[Sequence @@ list]] The use of Apply (@@) converts the List into a Sequence. Because the And function has the attribute HoldAll, you have to throw an Evaluate wrapper around the argument. -- P.J. Hinton Mathematica Programming Group paulh@wolfram.com Wolfram Research, Inc. http://www.wolfram.com/~paulh/ Disclaimer: Opinions expressed herein are those of the author alone.