## Chapter 18: lojbau mekso: Mathematical Expressions in Lojban

_{22. Four score and seven: a mekso problem}

_{Abraham Lincoln's Gettysburg Address begins with the
words “Four score and seven years ago”. This section exhibits
several different ways of saying the number “four score and
seven”. (A “score”, for those not familiar with the term, is
20; it is analogous to a “dozen” for 12.) The trivial
way:}

_{✥22.1 bize eight seven 87 }

_{✥22.1 is mathematically
correct, but sacrifices the spirit of the English words, which
are intended to be complex and formal.}

_{✥22.2 vo pi'i reno su'i ze four times twenty plus seven 4 × 20 + 7 }

_{✥22.2 is also mathematically
correct, but still misses something. “Score” is not a word
for 20 in the same way that “ten” is a word for 10: it
contains the implication of 20 objects. The original may be
taken as short for “Four score years and seven years ago”.
Thinking of a score as a twentysome rather than as 20 leads
to:}

_{✥22.3 mo'e voboi renomei su'i ze the-number-of four twentysomes plus seven }

_{In ✥22.3, “voboi renomei”
is a sumti signifying four things each of which are groups of
twenty; the “mo'e” and “te'u” then make this sumti into a
number in order to allow it to be the operand of
“su'i”.}

_{Another approach is to think of “score” as setting a
representation base. There are remnants of base-20 arithmetic
in some languages, notably French, in which 87 is
“quatre-vingt-sept”, literally “four-twenties-seven”. (This
fact makes the Gettysburg Address hard to translate into
French!) If “score” is the representation base, then we
have:}

_{✥22.4 vo pi'e ze ju'u reno four ; seven base 20 4720 }

Overall, ✥22.3 probably captures the flavor of the English best. ✥22.1 and ✥22.2 are too simple, and ✥22.4 is too tricky. Nevertheless, all four examples are good Lojban. Pedagogically, these examples illustrate the richness of lojbau mekso: anything that can be said at all, can probably be said in more than one way.