forms of Subjunctivity

pe'a, da'i, ja'acu'i, maybe also nu'o

One may say at the onset that pe'a is poetical, da'i rhetorical (cusku smuni), & ja'acu'i logical (logji smuni). To what extent do they differ, to what extent intersect? And what do these have to do with the part of Lojban left to inference (unexpressed sumti places, the relation of the units of a tanru)...?

why do you think ja'acu'i means logical? (I am using this in the sense described under Three-Value Logic".)

There is more than one way to think about this. For instance, "undecided"(3), or "neither true nor false"(2), or "both true and false"(1), or "neither true nor false, or both true and false, depending on context" (which i favor); plus various representations based on ternary diagrams (scissors/paper/rock or the primary color wheel...) & rotation.

As a lujvo: norje'u: "In-between-true-and-false". In fuzzy logic: ja'axipimu...

(1)jetnu je jitfa is, in Lojban, simply a contradiction; while

(2)jetnu najenai jitfa is the empty set.

(3) ju'ocu'i expresses uncertainty about a statement.

da'i (CLL):

"The discursive da'i marks the discourse as possibly taking a non-real-world viewpoint ('Supposing that', 'By hypothesis'), whereas da'inai insists on the real-world point of view ('In fact', 'In truth', 'According to the facts'). A common use of da'i is to distinguish between:

12.5) ganai da'i do viska le mi citno mensi

gi ju'o do djuno le du'u ri pazvau

If you (hypothetical) see my young sister,

then (certain) you know that she is-pregnant.

If you were to see my younger sister,

you would certainly know she is pregnant.

and:

12.6) ganai da'inai do viska le mi citno mensi

gi ju'o do djuno le du'u ri pazvau

If you (factual) see my young sister,

then (certainty) you know that she is-pregnant.

If you saw my younger sister,

you would certainly know she is pregnant.

It is also perfectly correct to omit the discursive altogether, and leave the context to indicate which significance is meant. (Chinese always leaves this distinction to the context: the Chinese sentence

12.7) ru2guo^3 ni^3 kan4dao^4 wo^3 mei4mei,

ni^3 yi2ding^4 zhi1dao^4 ta^1 huai2yun^4 le

if you see-arrive my younger-sister,

you certainly know she pregnant

is the equivalent of either Example 12.5 or Example 12.6.)"

Other discussions, that do not avoid loudcuckooland, are here & here.

However, i prefer to think of da'i as a way of representing one of the ways humans speak, without necessarily carrying a lot of philosophical baggage as to whether or not alternative realities in any sense "exist". I realize it is lobykai to make one's presuppositions explicit, but i have a strong hunch that future lobypre will not use da'i except to express (or translate) this tone of voice; whereas for true philosophical discussions they would create technical terms with exact meanings by means of cei broda.

le dei xanri as a metastatement.

pe'a (CLL):

As a tanru: sinxa selsku. One may note that, in Lojban anyway, you have to have something definite in mind when speaking fuguratively...

"The cmavo pe'a is the indicator of figurative speech, indicating that the previous word should be taken figuratively rather than literally:

13.2) mi viska le blanu pe'a zdani

I see the blue (figurative) house.

I see the blue house.

Here the house is not blue in the sense of color, but in some other sense, whose meaning is entirely culturally dependent. The use of pe'a unambiguously marks a cultural reference: blanu in Example 13.2 could mean 'sad' (as in English) or something completely different.

The negated form, pe'anai, indicates that what has been said is to be interpreted literally, in the usual way for Lojban; natural-language intuition is to be ignored.

Alone among the cmavo of selma'o UI, pe'a has a rafsi, namely pev. This rafsi is used in forming figurative (culturally dependent) lujvo, whose place structure need have nothing to do with the place structure of the components. Thus risnyjelca (heart burn) might have a place structure like:

x1 is the heart of x2, burning in atmosphere x3 at temperature x4

whereas pevrisnyjelca, explicitly marked as figurative, might have the place structure:

x1 is indigestion/heartburn suffered by x2

which obviously has nothing to do with the places of either risna or jelca."

nu'o (CLL):

"Consider once again the newly hatched ducks mentioned earlier. They have the potential of swimming, but have not yet demonstrated that potential. This may be expressed using nu'o, the cmavo of CAhA for undemonstrated potential:

19.7) ro cifydatka nu'o flulimna

all infant-ducks (can but has not) are-float-swimmers.

All infant ducks have an undemonstrated potential

for swimming by floating.

Baby ducks can swim but haven't yet."

(Contrastive to pu'i.)

• Notice though that there is an unmentioned but present fluid (probably water) in these relationships. This "undemonstrated potential" is not just of the ducks, but of every duck-water pair. It can be misleading to talk of a potential of the ducks, when what we have is in fact a potential relationship. We could just as well translate 19.7 as "water can be swam in by baby ducks but hasn't yet", which sounds very odd. I don't think time tenses should really be involved here, since none is mentioned. For example le vi cifydatka nu'o ba flulimna should mean "this little duck could but won't swim". --xorxes