# Sumti Places Requiring Sets

[20:31] <rlpowell> Now, get rid of gismu places that require sets: *fuck* yes.  But only the requirement, not the places.
[20:33] <Melvar> Do the places make sense without sets?
[20:33] <rlpowell> vensa: Also, I *do* try to listen, and respect people's objections and stuff.  :)  Just be nice, and I'll be nice back.
[20:34] <rlpowell> Melvar: They make sense with any distributive group.
[20:34] <Melvar> Exactly.
[20:34] <rlpowell> Which isn't just sets.
[20:34] <Melvar> What then?
[20:35] <rlpowell> In fact, most of them make *way* more sense with loi than lo'i
[20:35] <Melvar> Huh? Masses, distributive?
[20:35] <rlpowell> Example: kampu: x1 (property - ka) is common/general/universal among members of set x2 (complete set)
[20:36] <rlpowell> Erm, yes?  That's their entire purpose?
[20:36] <rlpowell> Masses are for "the students surrounded the building".  Use that example as your analogical case and you can't really go wrong.  :)
[20:36] <rlpowell> No one student is doing the surrounding.  The *set* of students certainly doesn't surround anything, because sets only have membership and cardinality.
[20:37] <rlpowell> Lojban calls the non-distributive plural "masses".
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[20:38] <rlpowell> vensa: ^^ and that's why sets are kind of pointless.
[20:38] <Melvar> Have you contradicted yourself or am I not understanding something important?
[20:39] <rlpowell> The *only* attributes sets have are membership and cardinality.  This makes them almost useless to say anything with outside of math.
[20:39] <rlpowell> Melvar: As far as I know everything I said makes sense; what doesn't make sense to you?
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[20:40] <Melvar> It seems to me that once you called masses distributive, and another time nondistributive, or else I misassigned a response â€¦
[20:41] <rlpowell> You're absolutely right.
[20:41] <rlpowell> < rlpowell> Melvar: They make sense with any distributive group. -- I meant non-distributive.
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[20:45] <paldanyli> Why does kampu make more sense with masses than sets?
[20:46] <rlpowell> paldanyli: Because sets only have cardinality and membership.
[20:46] <rlpowell> They have no other properties.
[20:47] <rlpowell> The only thing that's "common" to a set is, I dunno, the most frequent member or something?  It doesn't even really make sense.
[20:48] <Melvar> The way I thought of it is that the concept of membership makes a set act as a distributive.
[20:49] <paldanyli> It makes sense to me. We're talking about the members, no?
[20:49] <rlpowell> Distributiveness is exactly not-helpful here; that's why you can't do "kampu mi .e do", because that distributes to "kampu mi" and "kampu do"
[20:49] <rlpowell> Yeah, the idea is it's supposed to be "common among the members of the set", but "among the members of the mass" works just fine too.
[20:49] <rlpowell> And "common to the mass" also.
[20:50] <paldanyli> That doesn't make much sense to me. How could something be common in a mass? Perhaps I think of masses differently than everyone else.
[20:51] <Melvar> Masses donâ€™t have members, do they?
[20:51] <rlpowell> How could they not?
[20:51] <Melvar> âˆˆ is not defined on them.
[20:51] <rlpowell> I mean, if sets have members, I don't see how a mass could possibly not; they're both plural abstractions.
[20:51] <rlpowell> Umm.  Nothing mathematical is defined on masses; we made them up.
[20:52] <paldanyli> Wouldn't be much use if masses didn't have members. But if the purpose is to aggregate their properties, using them to get at their members properties seems strange.
[20:53] <rlpowell> That's true for sets, too. :)
[20:53] <paldanyli> Not to aggregate their properties. Just to indicate the membership.
[20:54] <rlpowell> To me, a mass of something has all of the properties of its members, in proportion to their frequency.  So the mass of rats is mostly X inches long, but somewhat Y inches long.
[20:54] <rlpowell> That view is probably idiosyncratic, though.
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[20:54] <paldanyli> That was my view as well. Which is why kampu on masses confuses me.
[20:55] <rlpowell> Well, something that is common to all of them is clearly a major part of the mass, yeah?
[20:55] <Melvar> kampu: p â†¦ A â†¦ âˆ€aâˆˆA:p(a)
[20:55] <rlpowell> I can't see most of that, sorry.
[20:56] <Melvar> Wait a sec.
[20:56] <paldanyli> I don't think there's any reason that masses couldn't serve as sets, but it's not what I think of their purpose as being. It's confusing to me to make a set then "break it apart".
[20:56] <paldanyli> Make a mass, rather.
[20:56] <rlpowell> Right, but whether you use a set or a mass there, you're asking about the members, not the set or the mass.
[20:56] <rlpowell> So I don't see that it matters much.
[20:57] <paldanyli> Probably not. I can't think of a property of sets that wouldn't apply to masses.
[20:58] <rlpowell> And this all is why I wouldn't suggest getting rid of sets; if it's this easy to argue about, it's not clear cut.  :D
[20:58] <Melvar> $kampu: p \mapsto { A \mapsto \forall a \in A : p(a) }$ approximately.
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[21:01] <paldanyli> I suppose the cardinality of a mass of masses would be in question.
[21:02] <paldanyli> Likewise its membership?
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[21:11] <rlpowell> I'd love it if you could summarize all this to the appropriate BPFK page, btw.  Perhaps the gadri one.