Prepositional Maps

We need to discriminate between

"the occurrence of...."

and

"the earlier to occur of...."

In linking "of" to the relation ToOccur, the first instance should succeed and the second instance should fail, but its failure should be pronounced.

Where there are multiple possibilities, maps should not only succeed and build things, they should fail and say it is not possible for this connection to exist. We can do this by using the existence of the head of the map as an indication of fitness, where fitness ranges from must to cannot.

There are some base (and other) forms of verb that support a following "of" –

To think of
He thought of
He was thinking of
To hear of

But most will not –

To occur of
To display of

We can have two maps, one which checks for the verb to be in a permitted set, and one which checks that it is not. It would be more efficient to have one map, where the existence value of the head was switched based on the presence in the set.

Another map handles the noun form, where almost all relations support a trailing of –

A display of
An occurrence of

The result is that we search for maps for a particular instance of a preposition. We may have returned a map that must be so, and we build the connection immediately. We may have returned a map which says it cannot be so, and we break the preceding object out of the chain (assuming it is a prepositional phrase), allowing the current preposition to acquire a new neighbour.

Breaking the preposition out of the chain is effectively doing a jump and rendering the prepositional noun phrase invisible (it can no longer be seen by prepositions on its right that are hunting for a subject).

There is a whole spectrum of fitness between these extremes of must and cannot, but these two will go a long way to unravelling a complex chain.

This is further evidence that truth and falsity are two sides of the same coin, and should be treated equally - see What Things Are Not.

Many of the prepositions in chains are not idly there to specify context, such as

"the fox in the woods"

but are there as part of a relation structure. These prepositions need to be treated differently - to be seen as components of a relation. As example

describedinplan.jpg (112321 bytes)

Here, the "in the plan" is a way of stating the subject of the "described" participial. The participial searches for trailing prepositions that should connect to it, rather than each preposition searching left for a suitable target. "attached as" is a special case of verb collocation - a new relation is inserted. Both "described" and "attached as" could lay claim to "Exhibit A", with

"premises described, in the plan attached as Exhibit A, as being suitable for office use"

being possible, where each relation can take up one of the descriptions. See Semantic Octopus for the ways that relations find prepositions as targets, simplifying the unravelling of prepositional chains.

Presentation on Prepositional Maps

Dynamic Constraint Reasoning for Prepositions

NLP