## Chapter 10: Imaginary Journeys: The Lojban Space/Time Tense System

### 21. Sub-events

Another application of non-logical tense connection is to talk about sub-events of events. Consider a six-shooter: a gun which can fire six bullets in succession before reloading. If I fire off the entire magazine twice, I can express the fact in Lojban thus:

```✥21.1    mi reroi pi'u xaroi
cecla le seldanti
I [twice] [cross-product] [six times]
shoot the projectile-launcher.
On two occasions, I fire the gun six times.```

It would be confusing, though grammatical, to run the “reroi” and the “xaroi” directly together. However, the non-logical connective “pi'u” expresses a Cartesian product (also known as a cross product) of two sets. In this case, there is a set of two firings each of which is represented by a set of six shots, for twelve shots in all (hence the name “product”: the product of 2 and 6 is 12). Its use specifies very precisely what occurs.

In fact, you can specify strings of interval properties and event contours within a single tense without the use of a logical or non-logical connective cmavo. This allows tenses of the type:

```✥21.2    la djordj. ca'o co'a ciska
George [continuitive] [initiative] writes.
George continues to start to write.

✥21.3 mi reroi ca'o xaroi darxi le damri
I [twice] [continuitive] [six times] hit the drum.
On two occasions, I continue to beat the drum six times.```