Section � CS187

Greg Detre

Wednesday, October 02, 2002

 

works back from goal

depth-first search

 

:- is an <- (implication arrow running backwards from forAll)

 

listing.

 

[cookie].

������ loads cookie.pl

 

no notion of falsity � only �can�t prove�

 

halt.

 

swipl

������ loads prolog

 

swi prolog

 

need to use �assert� when within the prolog bit

 

it can hang in an infinite loop

e.g. certain tautologies

 

when it gets really large, it�s often best to use it to query an external DB

it sorts things by cost (I thought it sorted things chronologically by when entered into the DB)

 

scott adams � wrote early text adventures � funny recording of a lecture

how would you do this two-word (verb-noun) system?

lookup table for pairs relativised to room/context

state of the world

or: invisible objects (e.g. lever-A-has-been-switched)

just keep a binary list of verbs that are applicable at a given moment

maintain place-states crossed with player-states

object-orientated?

each object maintains a list of the verbs that work on them (if there aren�t too many verbs in the system)

m (verbs) x n (nouns) � finite m actions with stereotyped results

make it more powerful by adding made-up verb-phrases, e.g. �light-with-match candle�

drawbacks?

limits complexity � can�t combine >1 object at a time

supplementary questions

difficult to ask questions � you can use interrogatory verbs (e.g. �examine�)

what is a verb anyway?

 

Admin

presentation is available online

Questions

�cut� operator

doesn�t Prolog get really slow???

american football text adventures on mobile phone

�NLP �service� or �oracle��???