Chapter 11
Events, Qualities, Quantities, And Other Vague Words: On Lojban Abstraction

1. The syntax of abstraction

The purpose of the feature of Lojban known as ``abstraction'' is to provide a means for taking whole bridi and packaging them up, as it were, into simple selbri. Syntactically, abstractions are very simple and uniform; semantically, they are rich and complex, with few features in common between one variety of abstraction and another. We will begin by discussing syntax without regard to semantics; as a result, the notion of abstraction may seem unmotivated at first. Bear with this difficulty until Section 2.

An abstraction selbri is formed by taking a full bridi and preceding it by any cmavo of selma'o NU. There are twelve such cmavo; they are known as ``abstractors''. The bridi is closed by the elidable terminator ``kei'', of selma'o KEI. Thus, to change the bridi

1.1)  mi klama le zarci
    I go-to the store

1.2)  nu mi klama le zarci [kei]
    an-event-of my going-to the store

(Technically, ``kei'' is never necessary, because the elidable terminator ``vau'' that closes every bridi can substitute for it; however, ``kei'' is specific to abstractions, and using it is almost always clearer.)

The grammatical uses of an abstraction selbri are exactly the same as those of a simple brivla. In particular, abstraction selbri may be used as observatives, as in Example 1.2, or used in tanru:

1.3)  la djan. cu nu sonci kei djica
    John is-an-(event-of being-a-soldier) type-of desirer.
    John wants to be a soldier.

1.4)  la djan. cu djica le nu sonci [kei]
    John desires the event-of being-a-soldier.

We will most often use descriptions containing abstraction either at the end of a bridi, or just before the main selbri with its ``cu''; in either of these circumstances, ``kei'' can normally be elided.

The place structure of an abstraction selbri depends on the particular abstractor, and will be explained individually in the following sections.

Note: In glosses of bridi within abstractions, the grammatical form used in the English changes. Thus, in the gloss of Example 1.2 we see ``my going-to the store'' rather than ``I go-to the store''; likewise, in the glosses of Example 1.3 and Example 1.4 we see ``being-a-soldier'' rather than ``is-a-soldier''. This procedure reflects the desire for more understandable glosses, and does not indicate any change in the Lojban form. A bridi is a bridi, and undergoes no change when it is used as part of an abstraction selbri.