CAhA as sumtcita

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Selma'o CAhA is a simple tag, like PU and ZAhO, and so can grammatically tag a sumti.

Let us suppose that ka'e is the same as su'omu'ei. Then naku ka'e is nomu'ei, ka'eku naku is me'iromu'ei, and naku ka'eku naku (= bi'ai) is romu'ei. Let us further say that ca'a also refers to possible worlds, like ka'e and bi'ai, and means in this world.


su'omu'eiku zo'u ganai le trene cu spofu gi mi jai lerci = su'omu'ei le du'u le trene cu spofu vau mi jai lerci = ka'e le du'u le trene cu spofu vau mi jai lerci
If the train breaks down, I could be late.

naku su'omu'eiku zo'u ganai mi tadni la lojban gi mi sipna = nomu'ei le du'u mi tadni la lojban vau mi sipna = naku ka'e le du'u mi tadni la lojban gi mi sipna
If I study Lojban, I necessarily don't sleep.

romu'eiku zo'u ganai mi megdo rupnu ponse gi mi ricfu = romu'ei le du'u mi megdo rupnu ponse vau mi ricfu = bi'ai le du'u mi megdo rupnu ponse vau mi ricfu
If I have a million dollars, I'm necessarily rich.

One can also use ca'a as a sumtcita, which would transfer the reference point for ca'a from this world to the world(s) in which the tagged proposition is true (like ca as a sumtcita transfers the reference point from the speaker's now to the time of the tagged event), and so I have a hard time coming up with a distinction between ca'a and bi'ai when used as a sumtcita, unless someone has a good suggestion. Thus, the last example could also be expressed as ca'a le du'u mi megdo rupnu ponse vau mi ricfu (see if).

  • xorxes:
    bi'ai claims the main bridi for all worlds in which the sumti is true. ca'a claims it for at least one world, namely this one. So I would understand ca'a le du'u mi megdo rupnu ponse vau mi ricfu to mean: "Having a million dollars, I am rich."
    • Adam:
      Would ca le nu mi megdo rupnu ponse vau mi ricfu then mean Since I have a million dollars now, I am rich?
      • xorxes:
        • Let's see if this works: In terms of mu'ei, we have ka'e = su'omu'ei and bi'ai = romu'ei. Now I would say that ca'a is to ka'e as le is to lo, where the world you have in mind is this world. If this holds, then the sumti of ca'a would restrict not to all worlds in which the proposition holds, but to all the worlds you have in mind, which you describe by that proposition. I think that would give something like "Having a million dollars (in those worlds I'm considering), I would be rich". This is weaker than "If I had a million dollars, I would be rich", which says that in all worlds in which I have a million dollars I'm rich, and corresponds to bi'ai le du'u mi megdo rupnu ponse vau mi ricfu. Maybe.
          • Certainly ca'a:ka'e::le:lo; however le and lo are not sumtcita, and so it's hard to see what to make of the analogy. ca also has a default of the speaker's reference point, but that is lost when it is used as a sumtcita, since a sumti tagged by ca is not claimed to happen now.
      • And Rosta:
        • I don't think ca'a is analogous to le. Rather it is analogous to nau; it is deictic. Just as nau means "the time and place of dei", so ca'a means "in possible worlds that include the world of dei". Therefore ca'a lo'e du'u mi megdo rupnu ponse vau mi ricfu would mean If I have a million rupnu (and in actual fact I do), then I am rich. Likewise, nu'o means "in possible worlds that do not include the world of dei", so nu'o lo'e du'u mi megdo rupnu ponse vau mi ricfu would mean "If I had a million dollars (and in fact I don't), then I would be rich". (So nu'o turns out to be the true way to do counterfactual conditionals.)
          • Adam:
            • nau sets the reference point; the default is the time and place of dei, but I don't see why its default wouldn't be overridden when it is used as a sumtcita, as is the case with other tags. Perhaps a better analogy to su'omei/ka'e, ca'a, romei/bi'ai is su'oroi, ca, roroi. Unfortunately, possible worlds aren't continuous in the way time is, so it's hard to derive a precription from that analogy. Is there any other tag (other than nau), whose meaning as a sumtcita is in effect "my default value is the same as the tagged sumti"? (i.e. ri'u le prenu means to the right of the person, not to my right, and that's also to the right of the person.)
          • And Rosta:
            • According to what I was saying above: The key thing is that ca'a and nu'o are deictic (regardless of whether they are tagging a sumti); I'm not saying that the analogy with nau extends beyond their deixis. They mean the same as su'o mu'ei lo'e du'u ko'a broda vau fo'e brode ("If ko'a is broda then it could be that fo'e is brode") except that ca'a says that the possible worlds covered by su'o include the world of dei and nu'o says the the possible worlds don't include the world of dei. Note, then, that ca'a broda does not quite mean "In dei-world, broda". Rather, that meaning is entailed by the actual meaning, "It could be, and in fact is, the case that broda" = "In some worlds, including dei-world, broda". The sumti tagged by ca'a serves to restrict the range of possible worlds quantified over.
          • xorxes:
            • Concerning: so nu'o lo'e du'u mi megdo rupnu ponse vau mi ricfu would mean If I had a million dollars (and in fact I don't), then I would be rich. (So nu'o turns out to be the true way to do counterfactual conditionals.)
              • I don't think that's right. The nu'o sentence has to mean: If I had a million dollars (and in fact I don't), then I could be rich, because nu'o is su'omu'ei excluding this one, not romu'ei excluding this one.
              • And Rosta:
                • Aye, you're right. Do we need a way to say "ro mu'ei-excluding-dei-world"? (E.g. should nu'oi become a ROI with this meaning?) Yes: I think the very example I gave in error proves its utility. But ro nu'oi broda - where nu'oi isn't tagging a sumti would not be very useful. What d'you reckon? Is a version of nu'oi in ROI the way to go? Or is the solution to in some way combine mu'ei with ca'a nai (though it seems to me that neither should be within the scope of the other)? (Sorry: my brain's a bit tired.)

With this interpretation of ka'e and ca'a:

  • the two tags act on the bridi as a whole, like normal lojban tenses, instead of on a single sumti (as would be implied by glossing ka'e as can).
    • la xod:
      I've heard Jorge suggest that CAhA is not like other tenses, and somehow only works on one sumti as you say. But I find that idea disturbingly irregular so I prefer to interpret it to affect the entire bridi, just like all the other tenses do, even if that makes no sense for some certain contrived cases.
      • Adam:
        xorxes' comments about ka'e and ca'a singling out a single place refer to their meaning when they are glossed as innately capable and actually is, and he complains about the irregularity as much as you do. The interpretation proposed on this page has no such problem.
        • xorxes:
          That is correct. I agree with Adam's presentation of ka'e as sumtcita.
  • ka'e nu (= su'omu'ei nu) is useful for discussing events which exist in the noosphere, whether or not they actually occur, whereas ca'a nu clearly insists that the event must actually occur in this world.
    • And Rosta:
      And nu'o nu for events that don't occur in dei-world.
  • allows for most of the semantics proposed for mu'ei without using experimental cmavo and without violating anything in the book or the baseline.
    • And Rosta:
      Although I am strongly in favour of (at least some close approximation of) your proposals, I do think they conflict with the book. See ca'ai, ka'ei and nu'oi', and nau'a'.
      • I suppose that it does conflict with the book to some degree, but the explanation in the book of ka'e is vague enough that I don't think that the problem is so bad.
    • ka'e and bi'ai do render mu'ei partly redundant, but:
      1. bi'ai adds an experimental cmavo, albeit an independently motivated one, so "getting rid of experimental cmavo" is not one of the current proposal's main selling points.
        • I hope that I can use ca'a as a tag instead of bi'ai, and there by use this if without any experimental cmavo, but this remains to be seen.
      2. Things like so'e mu'ei are still not redundant. The prima facie alternative for that, so'e cu'o, has ill-understood semantics and cannot function as a sumtcita.
        • I purposefully said that it allows for most of the semantics of mu'ei (at least the most common ones).
      3. ba'oi is not rendered redundant by these proposals, and its parallelism with mu'ei is then a reason for wanting to keep mu'ei
        • You have yet to write up your description of ba'oi and indicate how it is useful.
        • Whoops. Will do it when And Rosta have a moment.
    • And Rosta:
      ... therefore, looking at it as a pure design issue, I'd say that it'd be better to drop ka'e (from these proposals) and drop bi'ai and have mu'ei in their stead. That would leave ca'a and nu'o meaning "'su'o mu'ei-(not)-including-world-of-dei". This in turn would leave ka'e free to have its "capability" meaning now entrenched in some usage. Putative baseline-violation would then be confined to the little-used ca'a and nu'o'
      • Adam:
        I think that treating some members of CAhA differently from others isn't a good idea. Also, no matter what its interpretation, I'm nearly certain that ka'e is not simply an abbreviation for kakne, which seems to be mostly how it's used.
      • Fair enough. But the facts as And Rosta see them are:
        1. mu'ei can do everything that ka'e does, but ka'e cannot do everything that mu'ei does. IOW, mu'ei makes ka'e redundant, but ka'e doesn't make mu'ei redundant.
        2. Adam:
          To get cmavo with the meanings we want, we have to fight one of two battles. Either some or all members of CAhA need to be redefined from their documented meanings, or experimental cmavo (ca'ai, ka'ei and nu'oi, and nau'a) must be used. But at least the battle need be fought over ka'e for no other reason than harmony with the rest of CAhA. Personally I think it's good to have a few cmavo that can harmlessly be abused by people who don't care about rigour, so I'd happily wash my hands of ka'e and say "Here you are, do what you like with it, it won't offend my sensibilities...".
  • la xod:
    If broda ca le nu brode moves broda to the time when nu brode occurs, then shouldn't broda ka'e le nu brode move broda to the imaginary worlds where nu brode is possible?
    • nitcion.:
      I think it would, and that makes it a brilliant rendering of hypothetical 'if'. And while I'm at it, I think this use of ka'e is much more useful than 'innate capacity', which is utterly impossible to formalise. Count me in for this "subversion of the baseline": Kudos, Adam
      • la xod:
        Fine, just when we really didn't need yet another way to say "if". What does this make, seven now? What a shame that sumtcita ka'e couldn't have a more interesting meaning.
        • Adam:
          Which of those other ifs did you want to use for this meaning? For me, this finally more or less solves the problem of a general-purpose, formal if which claims neither too much nor too little, and for the most part without using experimental cmavo. What other meaning did you want to give to ka'e, etc. as as sumtcita?
      • And Rosta:
        None of the proposed cmavo-based ways to say "if" actually approximate the meaning of "if", except for the ones discussed on this page. This page is not providing "yet another way to say 'if'". Rather, it is going a long way towards resolving the issue of how to say 'if'.
  • la xod:
    If you guys think that the first satisfactory way to express conditionals in Lojban was discovered at long last in autumn 2002, then let's settle this in jboske instead of cluttering up this wiki page. We'll come back here when done.