OF connects certain verbs and adjectives to the word "of".
+---OF---+---J--+
| | |
I thought of something
They accused him of the crime
I am proud of you
In most cases, "of" can not modify verbs: "*I ran of the
house". With a few verbs it can, however, such as "think" and
"accuse". In such cases, "OF+" is treated like a complement
connector, disjoined with other connectors like TO+ and
TH+. In some cases, like "accuse", the verb also requires a
direct object preceding the "of" phrase; such verbs carry
"(O+ or B-) & {OF+}.
In other cases, such as "think", no object is used.
"Of" phrases can also modify certain adjectives: "I'm proud of you". Such adjectives have OF+ disjoined with their other complement connectors.
"Of", of course, is also a regular preposition (although it can only modify nouns, not verbs). To connect to its object in sentences like those above, "of" can simply use the same J link used in prepositional phrases. Thus "of" carries "J+ & (OF- or Mp-)".
OF is also used with gerunds, in cases where the gerund is being used with a determiner: "His chasing of the dog was unfortunate". See "S: Gerunds: The no complement / determiner case".
OFd is used with quantifying determiner phrases, such as "a number of". See the Jd link for an example and details.