This chapter is not about Lojban mathematics, which is explained in Chapter 18 , so the mathematical uses of lerfu strings will be listed and exemplified but not explained.
A lerfu string as function name (preceded by ma'o of selma'o MAhO):
Note the boi here to separate the lerfu strings fy. and xy. .
A lerfu string as subscript (preceded by xi of selma'o XI):
The parentheses are required because ny. lo prenu would be two separate sumti, ny. and lo prenu . In general, any mathematical expression other than a simple number must be in parentheses when used as a quantifier; the right parenthesis mark, the cmavo ve'o , can usually be elided.
All the examples above have exhibited single lerfu words rather than lerfu strings, in accordance with the conventions of ordinary mathematics. A longer lerfu string would still be treated as a single variable or function name: in Lojban,
.abu by. cy.
is not the multiplication
“a × b × c”
but is the variable
abc
. (Of course, a local convention could be employed that made the value of a variable like
abc
, with a multi-lerfu-word name, equal to the values of the variables
a
,
b
, and
c
multiplied together.)
There is a special rule about shift words in mathematical text: shifts within mathematical expressions do not affect lerfu words appearing outside mathematical expressions, and vice versa.