ba'a seems to be used in a mostly non-temporal sense. That is, it is rarely used to express "I expect that X will happen", but rather something like "I presume that X would be the case". A borderline-temporal case is to interpret it as "I presume that X will be the answer to my question".
ba'anai does seem to be unambiguously used to refer to things in the past.
ba'a do bazu djuno fi ro djedi
I expect that in the far future, you will know about every day.
.ua .i ba'anai
Oh yeah, I remember now.
.i y xu ro pipybanfi cu respa - ba'a na mabru
Are frogs reptiles? I don't expect them to be mammals.
.i lenu mi joi la tal. puzi casnu ti cu mukti lenu mi te preti fo do .i ba'a loi mlatu loi gerku cu zmadu leka kukte .i xu tugni
Me and Tal's recent discussion prompted me to ask you. I expect cats to taste better than dogs. Do you agree?
ma se xabju do vi la astn - ba'a vi la ubuty. xabju
Where near Austin do you live? Probably near UT.
ba'a do xabju le jecrsautkarolaina
You probably live in South Carolina.
I rule that usage to be in error, and that the temporal interpretation should remain/become the official interpretation.
ba'acu'i cumki fa le nu mi sutra bacru ta'i tu'a lo nu lo denpa cu jbini ro valsi
In my experience, it is possible for me to speak quickly with pauses between every word.
ko tcidu .i ba'anai do pante vu'e le za'i le banrglico cu bangu le jboskepre
Read it. I recall that you objected to the fact that the lojbanologists discussed in English.
ca'e le mi tubnu cu na'ebo marna tubnu
I say my pipe is a non-pot pipe.
ca'e la bais cu mulno
BAI is hereby done.
ca'e le re do cu simxu speni
I hereby pronounce that the two of you are mutual spouses.
I pronounce you husband and wife.
ja'o mi tolnelci le gejbirje
So, I dislike root beer.
ja'o do na prenu citka prenu
Then you cannot be a cannibal.
ja'o do gento
Then you must be Argentinian.
ja'o do se bangu le glico .e la lojban .enai lo drata
So you know only English and Lojban.
za'a cladu carvi .i ja'o carmi carvi
I can hear the loud sound of rain. So it must be raining heavily.
ro bu'a zo'u le ka bu'a cu xamgu .inaja la cev traji le ka bu'a .i le ka zasti cu xamgu .i ja'o la cev traji le ka zasti
Of all good properties, God is the entity that has the most of it. Existence is a good property. Hence, God is the entity that is the most existent of all.
ju'a loi xalka cu danfu .i mi na morji le preti
Alcohol is the answer. I can't remember the question.
ju'a ba'e ro da cu se senpi .ei
Everything should be doubted, I say.
.i tatpi joi xagji .i ka'u ca le cabdei mi na .ei citka je pinxe mu'i tu'a le lijda
I'm tired and hungry. Tomorrow I mustn't eat or drink for religious reasons.
.i ka'u so'a nanmu cu xebni .iku'i mi certu le ka .o'o zei cinmo
Almost all men hate something, but I am very good at being patient.
pe'i le nu ma'a na frili kakne le nu benji la nomoi cu mukti .ei le nu ma'a na troci le nu benji ja vecnu le remoi
In my opinion, the fact that we can't easily send the zeroth one should be a reason for us not to try to send and sell the second one.
ru'a no le prenu cu nanca lo zmadu be li 25
Presumably, none of the people are more than 25 years old.
.i ru'a mi milxe leka bilma
I am slightly ill, I assume.
se'o tunta le mi tamji .i da poi palci cu klama jibni
I know internally that it stabbed my thumb. Something evil was coming close.
.i le mi skami se tcana prenu cu krici le se go'i
su'a le skami se tcana prenu cu so'eroi bebna
- My server people believe that.
- Which goes to show that server people are stupid most of the time.
mi pu te cusku lo nu go'i .i su'anai samselmri
I was told that. E-mail, in particular.
ti'e lo bangu cu kensa vidru
They say that language is a virus from outer space.
ti'e le rokci pe la titan cu bisli jenai rokci
I hear that the "rocks" on Titan are actually made of ice, not rock.
.i le do cmene cu za'a xelso
I see that you have a Greek name.
.i za'a le ca me la taral. cu cnino
Apparently the present Taral is new.
The template for "ju'a" seems to have got slots for scalars by mistake. These have been removed.
"ba'a" is now explicitly temporal, which is in accordance with the CLL, but invalidates much usage.
Added clarificationary note that "za'a" is not restricted to visual observation.