Non-logical connectives

We have already seen one non-logical connective, joi. By non-logical, we mean that the truth of the combined terms does not depend on the truth of the individual components. It may not be true that la kris. bevri le pipno "Chris carries the piano", or la pat. bevri le pipno "Pat carries the piano", for example (to revisit an example from Lesson 4), even if it is true that la kris. joi la pat. bevri le pipno "Chris and Pat carry the piano."

Lojban has several other non-logical connectives; we'll cover the most frequently used ones:

• ce joins sumti (usually) into a set, rather than a mass like joi.

  We haven't said much about sets; and because sets are fairly abstract entities, as entities go, you don't often have occasion to talk about them. While you can say mi viska loi remna "I saw a mass of people", for example (you saw them as a bunch), you aren't likely to say mi viska lo'i remna "I saw a set of people."

  But as we have seen in the exercises, some gismu need sets in order to work. simxu, for example, takes as its x₁ a set. This is because the group of things or people in a mutual relationship needs to be well-defined: you've got to be able to say with certainty whether someone is involved in the relationship or not. The point of sets is that you can categorically say x belongs to the set or doesn't. The membership of masses is left much more nebulous, so saying "a bunch of people talk to each other" doesn't make as definite a statement. The same goes for cuxna 'choose': what you choose from in Lojban (x₃) is a set, because you normally have to be certain what belongs in the group you're choosing from, and what doesn't.

  So when you form a set out of several sumti, you connect them with ce. To say "Jyoti, Susan and Ranjeet talk to each other", you would say something like

  la djiotis. ce la suzyn. ce la ranjit. simxu lenu tavla

  or

  la djiotis. ce la suzyn. ce la ranjit. tavla simxu

  Similarly, if you pick one of Jyoti, Susan or Ranjeet, you would say

  mi cuxna pa da la djiotis. ce la suzyn. ce la ranjit.

• If you are referring to an ordered set — a sequence of things, in other words — then you use ce'o to place things in order. This gets invoked when you're compiling a list for whatever reason; for example, the Lojban alphabet is a sequence, and you'd list it as

  .abu ce'o by. ce'o cy. ce'o dy. ce'o .ebu ...

  and so on. This is what liste 'list' and porsi 'sequence' expect as their x₁ sumti.

• fa'u carries the meaning of respectively: it relates pairs of sumti cross-wise. If I were to say

  la suzyn. .e la djiotis. tavla la jan. .e la ranjit.

  that means that both Susan and Jyoti talk to both Zhang and Ranjeet. If I want to say that Susan only talked to Zhang, and Jyoti only to Ranjeet (i.e. "Susan and Jyoti talked to Zhang and Ranjeet, respectively"), a logical connective is not useful. Instead, I would use fa'u to connect both pairs of sumti:

  la suzyn. fa'u la djiotis. tavla la jan. fa'u la ranjit.
  Susan, cross-wise with Jyoti, talks to Zhang, cross-wise with Ranjeet.

• If you're talking about a range, you use bi'i to describe the range between the first thing and the second thing; so it corresponds to English between. If you want to say "I dropped my pencil somewhere between the office and the bar", you would describe the location "somewhere between the office and the bar" as le briju ku bi'i le barja. The whole sentence would come out as:

  mi falcru lemi pinsi vi le briju ku bi'i le barja

  Warning

  This selma'o, BIhI, like selma'o JOI to which all non-logical connectives belong, can join both sumti and selbri. So Lojban grammar requires you to terminate a sumti before JOI with ku.

• If the order of the things defining the range matters, you use bi'o. This corresponds to from... to... in English (though between covers both ordered and unordered intervals.) For example, "from 1 PM to 2 PM" is an interval lasting an hour; but "from 2 PM to 1 PM" would normally be interpreted as a 23-hour interval (1 pm the following day), since times in English are assumed to be presented in order. Lojban follows suit with li pavo lo'o bi'o li paci as a 23-hour interval. If I said li pavo lo'o bi'i li paci, the order of the two times would not matter at all; so I could still be talking about a one-hour interval instead.

  Tip: The selma'o BIhI needs all sumti terminated before it, not just normal sumti with le or lo. Since numbers are also sumti, you have to use the terminator corresponding to li, which is lo'o.