So far, lerfu words have only appeared in Lojban text when spelling out words. There are several other grammatical uses of lerfu words within Lojban. In each case, a single lerfu word or more than one may be used. Therefore, the term “lerfu string” is introduced: it is short for “sequence of one or more lerfu words”.
A lerfu string may be used as a pro-sumti (a sumti which refers to some previous sumti), just like the pro-sumti “ko'a”, “ko'e”, and so on:
9.1) .abu prami by.
A loves B
In Example 9.1, “.abu” and “by.” represent specific sumti, but which sumti they represent must be inferred from context.
Alternatively, lerfu strings may be assigned by “goi”, the regular pro-sumti assignment cmavo:
9.2) le gerku goi gy. cu xekri .i gy. klama le zdani
The dog, or G, is black. G goes to the house.
There is a special rule that sometimes makes lerfu strings more advantageous than the regular pro-sumti cmavo. If no assignment can be found for a lerfu string (especially a single lerfu word), it can be assumed to refer to the most recent sumti whose name or description begins in Lojban with that lerfu. So Example 9.2 can be rephrased:
9.3) le gerku cu xekri. .i gy. klama le zdani
The dog is black. G goes to the house.
(A less literal English translation would use “D” for “dog” instead.)
Here is an example using two names and longer lerfu strings:
9.4) la stivn. mark. djonz. merko .i la .aleksandr. paliitc. kuzNIETsyf. rusko
.i symyjy. tavla .abupyky. bau la lojban.
Steven Mark Jones is-American. Alexander Pavlovitch Kuznetsov is-Russian.
SMJ talks-to APK in Lojban.
Perhaps Alexander’s name should be given as “ru'o.abupyky” instead.
What about
9.5) .abu dunda by. cy.
A gives B C
Does this mean that A gives B to C? No. “by. cy.” is a single lerfu string, although written as two words, and represents a single pro-sumti. The true interpretation is that A gives BC to someone unspecified. To solve this problem, we need to introduce the elidable terminator “boi” (of selma'o BOI). This cmavo is used to terminate lerfu strings and also strings of numerals; it is required when two of these appear in a row, as here. (The other reason to use “boi” is to attach a free modifier — subscript, parenthesis, or what have you — to a lerfu string.) The correct version is:
9.6) .abu [boi] dunda by. boi cy. [boi]
A gives B to C
where the two occurrences of “boi” in brackets are elidable, but the remaining occurrence is not. Likewise:
9.7) xy. boi ro [boi] prenu cu prami
X all persons loves.
X loves everybody.
requires the first “boi” to separate the lerfu string “xy.” from the digit string “ro”.