10.20.  Logical and non-logical connections between tenses

Like many things in Lojban, tenses may be logically connected; logical connection is explained in more detail in Chapter 14 . Some of the terminology in this section will be clear only if you already understand logical connectives.

The appropriate logical connectives belong to selma'o JA. A logical connective between tenses can always be expanded to one between sentences:

Example 10.152. 

mi pu je ba klama le zarci
I [past] and [future] go-to the market.

I went and will go to the market.

means the same as:

Example 10.153. 

mi pu klama le zarci
I [past] go-to the market.
.ije mi ba klama le zarci
And I [future] go-to the market.

I went to the market, and I will go to the market.

Tense connection and tense negation are combined in:

Example 10.154. 

mi punai je canai je ba klama le zarci
I [past-not] and [present-not] and [future] go-to the market.

I haven't yet gone to the market, but I will in future.

Example 10.154 is far more specific than

Example 10.155. 

mi ba klama le zarci
I [future] go-to the market.

which only says that I will go, without claiming anything about my past or present. ba does not imply punai or canai ; to compel that interpretation, either a logical connection or a ZAhO is needed.

Tense negation can often be removed in favor of negation in the logical connective itself. The following examples are equivalent in meaning:

Example 10.156. 

mi mo'izu'anai je mo'iri'u cadzu
I [motion-left-not] and [motion-right] walk.

I walk not leftward but rightward.

Example 10.157. 

mi mo'izu'a naje mo'iri'u cadzu
I [motion-left] not-and [motion-right] walk.

I walk not leftward but rightward.

There are no forethought logical connections between tenses allowed by the grammar, to keep tenses simpler. Nor is there any way to override simple left-grouping of the connectives, the Lojban default.

The non-logical connectives of selma'o JOI, BIhI, and GAhO are also permitted between tenses. One application is to specify intervals not by size, but by their end-points ( bi'o belongs to selma'o BIhI, and connects the end-points of an ordered interval, like English from ... to ):

Example 10.158. 

mi puza bi'o bazu vasxu
I [past-medium] from…to [future-long] breathe.

I breathe from a medium time ago till a long time to come.

(It is to be hoped that I have a long life ahead of me.)

One additional use of non-logical connectives within tenses is discussed in Section 10.21 . Other uses will probably be identified in future.