Existential, Logical and Clausal Control

Existential Control

    Until the roof is fixed, the house can’t be sold.

Existential control of the ToSell relation.

    He will sell the house in the spring.

Logical control

soldhouse.JPG (48979 bytes)

Clausal Control

Clausal control asserts logical control of the object – it also connects to the object. The true logical forces a true existential connection from the operator.

How can this be done? We could use a special type of link that asserts this, or do we need two connections, so that we can insert a negation on the logical path without breaking the object path?

notsellhouse.JPG (51834 bytes)

We can assert a logical negative, but that cannot assert an existential true – it may have been impossible to sell the house.

cantsellhouse.JPG (41825 bytes)

If we assert an existential negative, that asserts a logical negative. The verb auxiliary controlled which connection was used – the logical or the existential.

Clausal Nouns

We also need to handle clausal nouns -

His premonition that the bridge would collapse proved correct.

The noun supports the clause - other nouns are - idea, concept, thought. The relation sets the noun true, and a connection to it takes over the clausal role. The clause is first treated as a relative pronoun clause, and turned into a clausal clause when being connected to a clausal noun.

premonition.JPG (72846 bytes)

Operators with Existential Control

authorisedsell.JPG (75560 bytes)

With a true logical input, the operator puts out a true existential.

notauthorisedsell.JPG (82615 bytes)

The false logical input puts out a false existential, which means the house cannot be sold.

Negation of the existence of the authorisation eliminates its output.

Operators with Clausal Control

We can make operators with clausal control have an extra link, which they sprout on receiving a logical value. That is

HeSaid1.JPG (73485 bytes)

The discourse provides a logical value. The operator responds by attaching a link to the operator controlled by the clausal operator and propagating the incoming value. The operator remains a RELATION3, as the logical connection is orthogonal to its parameters.

HeSaid2.JPG (79156 bytes)

The state propagates down, but not necessarily back. If it turns out the house is not sold, the ToSell relation is negated, but that does not negate what was said.