Special predicates

[afader]

We should be able to handle queries like this:

(obama, born in, $x) ($x, is, date)

without having to add a bunch of (1945, is, date)-type triples to the triplestore. So there should be some special query-execution logic to test whether something is a date.

Other special predicates:

• gender
• person
• location
• "meta" things, like ($x, starts with letter, A)

[afader]

Another good special predicate would be quantities, that return true for strings like 23 people or one electron.