Chapter 12
Dog House And White House: Determining lujvo Place Structures

1. Why have lujvo?

1.1)  ti fagri festi
    That is-fire waste.

1.2)  ti fagyfesti
    That is-fire-waste.
    That is-ashes.

Although the lujvo ``fagyfesti'' is derived from the tanru ``fagri festi'', it is not equivalent in meaning to it. In particular, ``fagyfesti'' has a distinct place structure of its own, not the same as that of ``festi''. (In contrast, the tanru does have the same place structure as ``festi''.) The lujvo needs to take account of the places of ``fagri'' as well. When a tanru is made into a lujvo, there is no equivalent of ``be ... bei ... be'o'' (described in Chapter 5) to incorporate sumti into the middle of the lujvo.

So why have lujvo? Primarily to reduce semantic ambiguity. On hearing a tanru, there is a burden on the listener to figure out what the tanru might mean. Adding further terms to the tanru reduces ambiguity in one sense, by providing more information; but it increases ambiguity in another sense, because there are more and more tanru joints, each with an ambiguous significance. Since lujvo, like other brivla, have a fixed place structure and a single meaning, encapsulating a commonly-used tanru into a lujvo relieves the listener of the burden of creative understanding. In addition, lujvo are typically shorter than the corresponding tanru.

There are no absolute laws fixing the place structure of a newly created lujvo. The maker must consider the place structures of all the components of the tanru and then decide which are still relevant and which can be removed. What is said in this chapter represents guidelines, presented as one possible standard, not necessarily complete, and not the only possible standard. There may well be lujvo that are built without regard for these guidelines, or in accordance with entirely different guidelines, should such alternative guidelines someday be developed. The reason for presenting any guidelines at all is so that Lojbanists have a starting point for deciding on a likely place structure --- one that others seeing the same word can also arrive at by similar consideration.

If the tanru includes connective cmavo such as ``bo'', ``ke'', ``ke'e'', or ``je'', or conversion or abstraction cmavo such as ``se'' or ``nu'', there are ways of incorporating them into the lujvo as well. Sometimes this makes the lujvo excessively long; if so, the cmavo may be dropped. This leads to the possibility that more than one tanru could produce the same lujvo. Typically, however, only one of the possible tanru is useful enough to justify making a lujvo for it.

The exact workings of the lujvo-making algorithm, which takes a tanru built from gismu (and possibly cmavo) and produces a lujvo from it, are described in Chapter 4.