Bo, coming back to you late, now home from a Maine vacation. Comments are inserted in your note. Kip
Bo Jacoby wrote: > This discussion on sets seems to be strictly on FINITE sets. No infinite set > is represented by an array in J. Right? > Right. It might be possible to simulate an infinite sequence as a verb that emits terms as required. > A finite sets are conveniently represented by characteristic function also > called an indicator function, where f(x)=1 if x is an element of the set, and > f(x)=0 otherwise. > This is useful for representing individually all the subsets of some given set, but it would not allow you to represent a set some of whose members are themselves sets. > In J indicator functions are implemented simply bit arrays, which are easily > manipulated in J. What is the problem? > You would have no problem as long as you didn't need to deal with sets some of whose members are sets. > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
