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Chapter 11. Putting it together: Lojban
connectives
All languages need ways to connect words, phrases and sentences. In English there are a host of words
for this purpose: and, or, because, additionally, however, on the other hand ... the list seems endless, as
foreign students of English know all too well. Lojban also has a wide variety of words like this, known
as connectives, but it is more systematic about it. (Lojban also handles some of the functions of English
conjunctions in other ways—as we saw, because and so are translated with sumti tcita, not connectives.)
There are two types of connective: logical and non-logical. Logical connectives say something about
whether and in what circumstances the two things connected are true; an example is .ije. Non-logical
connectives do not deal with separate truth values, but group things together to form different kinds of
units; an example is joi, which we’ve already seen in passing, and we’ll be discussing again below.
Moreover, Lojban distinguishes between the logical component of connectives, and their attitudinal
content. For example, most languages have different words for and and but. Logically, they both mean
the same thing. In terms of attitude, however, they are different: but contains a connotation of contrast
or unexpectedness, which and does not. So Lojban translates but in two parts: .e ku’i ‘and—however’.
This follows the Lojban principle of keeping content and attitude separate as far as possible (e.g. .ui la
djiotis. klama ti has a content element—the information that Jyoti is coming here, and an attitude
element—happiness.)
In this lesson we will only look at logical connectives; non-logical connectives (with one exception) will
be dealt with later, along with some other attitudinals.
Types of logical connectives
In order to understand Lojban connectives, we first need to look at logical connectives in general. The
types of logical connective in Lojban are based on truth tables and are explained in detail in Chapter 14
of The Complete Lojban Language. However, if you’re not a logician, this can be rather confusing, so here
I’ll look at them in terms of Boolean operators. If you haven’t a clue what a Boolean operator is, don’t
panic; they are very simple, and you may even have used them in an internet search without realising
it. On the other hand, if you’ve used Boolean operators in maths or computer programming, the rest is
a piece of cake. The operators we will look at here are AND, OR, EOR, IF and IFF.
We have already looked at one operator: AND. A statement with AND is true if and only if both
elements are true. For example, if you do an internet search for “games AND strategy”, the search
engine will only come up with pages that contain both games and strategy: you will get pages on
strategy games, for example, but not (ideally) on simulation games or military strategy. Similarly in
Lojban
la flufis. ractu .ije ro ractu na’e ze’u jmive
is false if Fluffy is not a rabbit, or if some rabbits are long-lived. It is only true if both sentences are
true.