R help - Oct 2004 - setClass - equvalent declarations?

Hi,

Why the third declation is not equivalent to the first 2 and gives a Warning

#1
setClass("MVE",representation("list",names="character"))

#2

setClass(
         "MVE"
         ,contains="list"
         ,representation(
                        names="character"
                        )
         )
#3
setClass("MVE","matrix",representation(names="character"))

[1] "MVE"
Warning message: 
prototype is a list with named elements (could be ambiguous):  better to use
function prototype() to avoid trouble. in: reconcilePropertiesAndPrototype(name,
slots, prototype, superClasses,


/E.



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Dipl. bio-chem. Witold Eryk Wolski         
MPI-Moleculare Genetic
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