MYLONAS demonstrated only a very small portion, beginning with primary texts and running off the CD-ROM. Having selected Aeschylus' Prometheus Bound, which was viewable in Greek and English pretty much in the same segments together, MYLONAS demonstrated tools to use with the Greek text, something not possible with a book: looking up the dictionary entry form of an unfamiliar word in Greek after subjecting it to Perseus' morphological analysis for all the texts. After finding out about a word, a user may then decide to see if it is used anywhere else in Greek. Because vast amounts of indexing support all of the primary material, one can find out where else all forms of a particular Greek word appear-- often not a trivial matter because Greek is highly inflected. Further, since the story of Prometheus has to do with the origins of sacrifice, a user may wish to study and explore sacrifice in Greek literature; by typing sacrifice into a small window, a user goes to the English-Greek word list--something one cannot do without the computer (Perseus has indexed the definitions of its dictionary)--the string sacrifice appears in the definitions of these sixty-five words. One may then find out where any of those words is used in the work(s) of a particular author. The English definitions are not lemmatized. All of the indices driving this kind of usage were originally devised for speed, MYLONAS observed; in other words, all that kind of information-- all forms of all words, where they exist, the dictionary form they belong to--were collected into databases, which will expedite searching. Then it was discovered that one can do things searching in these databases that could not be done searching in the full texts. Thus, although there are full-text searches in Perseus, much of the work is done behind the scenes, using prepared indices. Re the indexing that is done behind the scenes, MYLONAS pointed out that without the SGML forms of the text, it could not be done effectively. Much of this indexing is based on the structures that are made explicit by the SGML tagging. It was found that one of the things many of Perseus' non-Greek-reading users do is start from the dictionary and then move into the close study of words and concepts via this kind of English-Greek word search, by which means they might select a concept. This exercise has been assigned to students in core courses at Harvard--to study a concept by looking for the English word in the dictionary, finding the Greek words, and then finding the words in the Greek but, of course, reading across in the English. That tells them a great deal about what a translation means as well.