PLEASE NOTE: THIS IS AN OLD VERSION. The current version is linked from The Complete Lojban Language.

12. Modal conversion: JAI

The following cmavo are discussed in this section:

   jai JAI modal conversion
    fai FA  modal place structure tag
So far, conversion of numbered bridi places with SE and the addition of modal places with BAI have been two entirely separate operations. However, it is possible to convert a selbri in such a way that, rather than exchanging two numbered places, a modal place is made into a numbered place. For example,
12.1)    mi cusku bau la lojban.
    I express [something] in-language Lojban.
has an explicit x1 place occupied by ``mi'' and an explicit ``bau'' place occupied by ``la lojban.'' To exchange these two, we use a modal conversion operator consisting of ``jai'' (of selma'o JAI) followed by the modal cmavo. Thus, the modal conversion of Example 12.1 is:
12.2)    la lojban. jai bau cusku fai mi
    Lojban is-the-language-of-expression used-by me.
In Example 12.2, the modal place ``la lojban.'' has become the x1 place of the new selbri ``jai bau cusku''. What has happened to the old x1 place? There is no numbered place for it to move to, so it moves to a special ``unnumbered place'' marked by the tag ``fai'' of selma'o FA.

Note: For the purposes of place numbering, ``fai'' behaves like ``fi'a''; it does not affect the numbering of the other places around it.

Like SE conversions, JAI conversions are especially convenient in descriptions. We may refer to ``the language of an expression'' as ``le jai bau cusku'', for example.

In addition, it is grammatical to use ``jai'' without a following modal. This usage is not related to modals, but is explained here for completeness. The effect of ``jai'' by itself is to send the x1 place, which should be an abstraction, into the ``fai'' position, and to raise one of the sumti from the abstract sub-bridi into the x1 place of the main bridi. This feature is discussed in more detail in Chapter 11. The following two examples mean the same thing:

12.3)    le nu mi lebna le cukta
        cu se krinu le nu mi viska le cukta
    The event-of I take the book
        is-justified-by the event-of I see the book.
    My taking the book is justified by my seeing it.

12.4) mi jai se krinu le nu mi viska le cukta kei
        [fai le nu mi lebna le cukta]
    I am-justified by the event-of I see the book
        [namely, the event-of I take the book]
    I am justified in taking the book by seeing the book.
Example 12.4, with the bracketed part omitted, allows us to say that ``I am justified'' whereas in fact it is my action that is justified. This construction is vague, but useful in representing natural-language methods of expression.

Note: The uses of modals discussed in this section are applicable both to BAI modals and to ``fi'o''-plus-selbri modals.