*Prelude:
Dataspace 0: Those Memex Dreams Again
Dataspace 1: In Search of a Data Model
Dataspace 2: Revenge of the Data Model
Dataspace 3: It Came From The S-Expressions
Dataspace 4: The Term-inator*

I want a Memex. Roughly, I want some kind of personal but shareable information desktop where I can enter very small pieces of data, cluster them into large chunks of data, and – most importantly – *point to any of these small pieces of data from any of these chunks*.

‘Pointable data’ needs a data model. The data model that I am currently exploring is what I call term-expressions (or T-expressions): a modified S-expression syntax and semantics that allows a list to end with (or even simply be, with no preceding list) a *logical term* in the Prolog sense.

Looking at term-expressions, one of the first things we notice is that there are a large number of null-like terms. I’m wondering what the meaning of these varieties of null might be.

- The simplest null-like term is the
*nil pair*or*empty list:*() - The next one is the
*empty term*: (/) - Then we have the
*empty set*(if can think of /all as a set) or*empty union*: (/all) - Then, for every other term functor X, the empty X: (/X)

An interesting question is whether *terms* correspond to *types*, (and if so, in what particular type system) or whether the notion of ‘type’ is unrelated to what we’re looking at here.

Continue reading Dataspace 9: A Tower of Nulls, And Awkward Sets