## 10.17. Tensed logical connectives

The Lojban tense system interacts with the Lojban logical connective system. That system is a separate topic, explained in Chapter 14 and touched on only in summary here. By the rules of the logical connective system, Example 10.117 through Example 10.119 are equivalent in meaning:

Example 10.117.

 la teris. satre le mlatu .ije la teris. satre le ractu
 Terry strokes the cat. And Terry strokes the rabbit.

Example 10.118.

 la teris. satre le mlatu gi'e satre le ractu
 Terry strokes the cat and strokes the rabbit.

Example 10.119.

 la teris. satre le mlatu .e le ractu
 Terry strokes the cat and the rabbit.

Suppose we wish to add a tense relationship to the logical connective and? To say that Terry strokes the cat and later strokes the rabbit, we can combine a logical connective with a tense connective by placing the logical connective first, then the tense, and then the cmavo bo, thus:

Example 10.120.

 la teris. satre le mlatu .ijebabo la teris. satre le ractu
 Terry strokes the cat. And then Terry strokes the rabbit.

Example 10.121.

 la teris. satre le mlatu gi'ebabo satre le ractu
 Terry strokes the cat, and then strokes the rabbit.

Example 10.122.

 la teris. satre le mlatu .ebabo le ractu
 Terry strokes the cat and then the rabbit.

Example 10.120 through Example 10.122 are equivalent in meaning. They are also analogous to Example 10.117 through Example 10.119 respectively. The bo is required for the same reason as in Example 10.110: to prevent the ba from functioning as a sumti tcita for the following sumti (or, in Example 10.121, from being attached to the following selbri).

In addition to the bo construction of Example 10.120 through Example 10.122, there is also a form of tensed logical connective with keke'e (tu'etu'u for sentences). The logical connective system makes Example 10.123 through Example 10.125 equivalent in meaning:

Example 10.123.

 mi bevri le dakli .ije tu'e mi bevri le gerku I carry the sack. And ( I carry the dog.
 .ija mi bevri le mlatu tu'u And/or I carry the cat ).
 I carry the sack. And I carry the dog, or I carry the cat, or I carry both.

Example 10.124.

 mi bevri le dakli gi'eke bevri le gerku gi'a bevri I carry the sack and (carry the dog and/or carry
 le mlatu the cat).
 I carry the sack, and also carry the dog or carry the cat or carry both.

Example 10.125.

 mi bevri le dakli .eke le gerku .a le mlatu I carry the sack and (the dog or the cat).
 I carry the sack and also the dog or the cat or both.

Note the uniformity of the Lojban, as contrasted with the variety of ways in which the English provides for the correct grouping. In all cases, the meaning is that I carry the sack in any case, and either the cat or the dog or both.

To express that I carry the sack first (earlier in time), and then the dog or the cat or both simultaneously, I can insert tenses to form Example 10.126 through Example 10.128:

Example 10.126.

 mi bevri le dakli .ije ba tu'e mi bevri le gerku I carry the sack. And [future] ( I carry the dog.
 .ija cabo mi bevri le mlatu tu'u And/or [present] I carry the cat. )
 I carry the sack. And then I will carry the dog or I will carry the cat or I will carry both at once.

Example 10.127.

 mi bevri le dakli gi'e bake bevri le gerku I carry the sack and [future] (carry the dog
 gi'a cabo bevri le mlatu and/or [present] carry the cat).
 I carry the sack and then will carry the dog or carry the cat or carry both at once.

Example 10.128.

 mi bevri le dakli .e bake le gerku I carry the sack and [future] (the dog
 .a cabo le mlatu and/or [present] the cat).
 I carry the sack, and then the dog or the cat or both at once.

Example 10.126 through Example 10.128 are equivalent in meaning to each other, and correspond to the tenseless Example 10.123 through Example 10.125 respectively.