Et Tu Brutus? Topic Maps and Discourse Semantics

TM as a semantic technology

Brutus killed Cesar with a dagger.

Clearly, although Cesar must have seen, when entering the Senate in Rome on the Ides of March in 44 BC that Brutus, aka Marcus Junius Brutus, was cheesed off because he had chatted up Porcia, Brutus’ wife, he did not expect that he might be brutally murdered by Brutus with a dagger. He had, therefore, not bought Band-Aid at Forum Romanum, although the market was open on that day, it being a weekday.

Modeling discourse: information about

• Some possible world or domain

• Some speaker’s or writer’s view of that world

• And the way this speaker or writer has chosen to structure and convey this information on a particular occasion.

Discourse meaning

• Propositional meaning

• Grammatical meaning

• Modal meaning

• Textual meaning

Discourse meaning

• Propositional meaning typically involves real world entities, events and situations and should therefore, as default, be encoded using topics and associations.

• Grammatical meaning typically represents properties of real world entities, events and situations and should therefore, as default, be encoded using internal occurrences.

• Modal meaning typically reflects the validity of statements on the part of the speaker or writer and should therefore, as default, be encoded using scope.

• Textual meaning is typically used to facilitate the elaboration, enhancement or extension of information and should therefore, as default, be encoded using reification.

Propositional meaning I

Brutus killed Cesar mercilessly with a dagger in the Senate on the Ides of March

kill(agent : brutus, goal : cesar, instrument : dagger, manner : mercilessly, place : senate, time : ides)

Propositional meaning II

Brutus killed Cesar mercilessly with a dagger in the Senate on the Ides of March

Brutus killed Cesar mercilessly with a dagger on the Ides of March in the Senate

* Brutus killed Cesar in the Senate on the Ides of March with a dagger mercilessly

Propositional meaning III

a) kill(agent : brutus, goal : cesar) ~brutus-kill-cesar#Brutus kill Cesar

b) proposition(nucleus : brutus-kill-cesar, manner : mercilessly, instrument : dagger) ~brutus-kill-cesar-mercilessly-with-a-dagger#Brutus kill Cesar mercilessly with a dagger

c) proposition(nucleus : brutus-kill-cesar-mercilessly-with-a-dagger, time : ides, place: senate)#Brutus kill Cesar mercilessly with a dagger on the Ides of March in the Senate

Grammatical meaning

kill(agent : brutus, goal : cesar, instrument : dagger ~instrument-dagger) ~brutus-kill-cesar-with-dagger

brutus-kill-cesar-with-daggertense: "past";aspect: "imperfective".

instrument-dagger is a daggerdefiniteness: "definite".

dagger.

Modal meaning I

kill(agent : brutus, goal : cesar) ~brutus-kill-cesar@probabilitybrutus-kill-cesartense: "past ".#Brutus may have killed Cesar

kill(agent : brutus, goal : cesar) ~brutus-kill-cesar@likelihoodbrutus-kill-cesartense: "future".#Brutus will probably kill Cesar

Modal meaning II

No way, Brutus may have killed Cesar

Textual meaning I

a) Brutus was cheesed off because Cesar had chatted up Porcia.

b) Cesar expected an attack. Therefore, he had bought Band-Aid.

c) Brutus killed Cesar. Then he fled Rome. It was one mistake after another.

Textual meaning II

Brutus was cheesed off because Cesar had chatted up Porcia.

cheesed-off(subject : brutus, reason : cesar-chatting-up-porcia)

Textual meaning III

Cesar expected an attack. Therefore, he had bought Band-Aid

reason-result(reason : cesar-expecting-attack, result : cesar-buying-band-aid)

Textual meaning IV

Brutus killed Cesar. Then he fled Rome. It was one mistake after another.

time-sequence(before : brutus-killing-cesar, after : brutus-fleeing-rome) ~brutus-killing-cesar-and-then-fleeing-rome

evaluation(evaluated : brutus-killing-cesar-and-then-fleeing-rome, evaluation : one-mistake-after-another)

Other discourse phenomena

• Appositions and genitives (e.g. Cesar had chatted up Porcia, Brutus’ wife)

• Cohesion (e.g. the fact that the Ides of March in 44 BC, on that day and it refer to the same thing and that Forum Romanum is also the market)

Reifying role playing topics

Cesar chatted up Porcia, Brutus’ wife

married(husband : brutus, wife : porcia ~wifeporcia)

chat-up(agent : cesar, goal : wifeporcia) ~cesar-chatting-up-porcia

Why encode discourse in TM?

• Discourse as topic maps (i.e. discourse is prior to the topic map).

• Topic maps as discourse (topic map is prior to discourse)