*** Guide-to-Links ***
I connects certain verbs with infinitives.

        +-S-+--I-+                    +S-+-O--+   |
        |   |    |                    |  |    |   |
	I must  go to the store       I made him  go

Infinitive verb forms have "I-", conjoined with their
complement connectors. In every case except "be", the
infinitive form is the same as the plural form; therefore the
same expression can be used. Plural-infinitive forms thus
carry "(Ss- or I- or Wi-) & [complement]". (The Wi- is used
to connect to the wall in imperative constructions.)

Modal verbs - "will", "may", "can", and the like - have I+
connectors; certain other verbs do as well, such as "do" and
"help". Some verbs have I+ conjoined with O+, like "make" and
"see", allowing an object followed by an infinitive. In these
latter cases, the infinitive verb relates to the direct object
of the main verb; it is similar in this respect to
object+infinitive constructions like "I want him to go". Thus
it is appropriate to include the O and I link in their own
domain. For this reason, we label the I+ connector on such
verbs as "I*j+", and make this an "urfl-domain"-starting link,
including both the O and the I*j. (See "TOo".)

The word "to" also has an "I+", conjoined with "TO-", used in
"to+infinitive" constructions. 

Modal verbs are almost always used with an infinitive.
However, occasionally the infinitive is omitted: "If you
cannot do it, you should find someone who can". For this
reason, modals are given "S- & (I+ or [[()]])"; this allows
them to make no connection to an infinitive, with a cost of
2. "Do" is similar in this respect.

"I#a" is used in object-type infinitival indirect questions.
Here, a "to"+infinitive construction occurs, but in this case
- unlike other "to"+infinitive constructions - the "to" is
unable to connect back to another word.

                   |   +I#a+
                   |   |   |
	I wonder what to  buy

Post-processing insures that I#a is only used in the same group
as a B#w or B#m, thus preventing unwanted uses of this

In infinitival indirect questions with "where/when/how" - "I
wonder where to go" - the question word instead makes a TOn
connection with "to". See "TO: Other kinds of TO connectors".

"If" connectors are used by post-processing to enforce the
correct use of "filler-it" and "there". See "SF: Filler-it".
I#d and Ix are used to prevent the unwanted construction "He
does be..". Forms of "do" carry I#d+; "be" carries Ix-; Ixd is
prohibited in post-processing.

Grammar Documentation Page.