*** Guide-to-Links ***
M
M connects nouns to various kinds of post-nominal modifiers 
without commas, such as prepositional phrases, participle
modifiers, prepositional relatives, and possessive
relatives. (Phrases of these kinds with commas use MX; see
"MX".) 

     Contents
     1. Words taking @M+
     2. "M" modifiers used with relative clauses
     3. Mp: Prepositional phrases modifying nouns
     4. Ma: Adjectival modifiers
     5. Mv and Mg: Participle modifiers
     6. Mv+, Mg+ used on conjunctions
     7. Mr: Possessive relatives
     8. Mj: Prepositional-object relative clauses
     9. M with "not"

Words taking @M+
Nouns have optional "@M+" connectors, conjoined with their
main "S+ or O- or J-..." expression and with their "{@A-} &
D-". Other words carrying @M+ include certain determiners that
can act as complete noun-phrases ("many", "some"), words like
"something" and "everyone", and numbers. Pronouns do not. This
yields

         +-M--+
         |    |
    The man from London is here
  Something with garlic would be good
	Some of the programmers are excellent
	Five of the programmers are excellent

	*She of the programmers is excellent

"M" modifiers used with relative clauses
Most kinds of post-nominal modifiers use "M" connectors to
connect to the previous noun. The except is relative clauses:
these do not use M+, but rather "R+ & B+" (see "R"). 
Note that words that take @M+ connectors have the following
expression:

        ...{@M+} & {R+ & B+ & {[[@M+]]}}...

Nouns frequently take a relative clause, or one or more
prepositional phrases; they rarely take both.  Occasionally
they do, however: "The picture that I showed you of Jane",
"The picture of Jane that I showed you". Therefore we have to
allow "@M+" and "R+ & B+" both conjoined and disjoined, in
either order; this is what the above expression
provides. There is still something rather arbitrary about
this, however. We allow any number of M connections
(prepositional phrases, participle modifiers, etc.) to be
made, or one relative clause followed or preceded by any
number of M connections, but not multiple relative
clauses. This was necessitated by the fact that relative
clauses require two conjoined connectors, and there is no way
of allowing indefinitely many "R+ & B+" connections to a
word. In practice, however, multiple relative clauses are
extremely rare.

Mp: Prepositional phrases modifying nouns
"Mp" is used for prepositional phrases modifying nouns.
Prepositions therefore have Mp- connectors directly disjoined
with MVp- (used for prepositional phrases modifying verbs) and
conjoined with J+ (used for prepositional objects). (Some
prepositions can take other kinds of objects besides
noun-phrases, and thus have other connectors conjoined with
"MVp- or Mp-": see "MV: Words taking MV-".)  Almost all words
that have Mp- also have MVp-; one exception is "of", which can
modify nouns but not verbs ("*The dog ran of the yard").  (A
few verbs can be modified by "of": see "OF".)

It was mentioned that many determiners and numbers also
have M+ connectors, as well as nouns. Thus the sentences
below are all linked in essentially the same way:

                    +-Mp+---J------+
                    |   |          |
	1. The salaries of the programmers are excellent
	2.         Some of the programmers are excellent
	3.         Five of the programmers are excellent

This may seem counterintuitive. In ex. 1, the subject
of "are" is "salaries"; in ex. 2 and ex. 3, it is really
"programmers". We see no need to make this distinction,
however. As well as the special use of "some" and "five"
shown here, these words can act as independent noun-phrases
taking no modifying phrase or quite different modifying
phrases (ex. 4 and 5); and even constructions like ex.
2 and 3 above sometimes arise where it is quite clear that
"some", not the prepositional object, is the real subject
(e.g., ex. 7).

	4. Some are excellent
	5. Some with doctorates are excellent
	6. Some holding doctorates are excellent
	7. (Most of the pictures of the executives are 
		terrible, but) 
		some of the programmers are excellent

An object of a prepositional phrase may, of course, take its
own prepositional phrase (or other modifying phrase). Since a
noun may also take multiple modifying phrases, this frequently
leads to ambiguity.  In addition, of course, prepositional
phrases may modify verbs, using MV-. In the sentence "I saw a
dog in the park by the river", for example, "by the river" may
modify "saw", "dog", or "park".

Mpc relates to comparatives; see "MV: Comparatives III".

Ma: adjectival modifiers
Ma connects nouns with post-nominal adjectival modifiers. 

                             +-Ma--+
                             |     |      
	These are people unhappy about the economy
	This is a trial certain    to attract attention

This is only correct when the adjective has some kind of
complement or modifier attached to it: "*These are people
unhappy", "*This is a trial certain". We enforce this in
post-processing. Ma connectors start a domain; post-processing
then requires that a group containing an Ma contain one of a
list of link-types, either complement links like "TO" or "TH",
or the prepositional phrase link MVp.

Mam relates to comparatives; see "MV: Comparatives II".

Max is used for a few adjectives which can be used post-nominally
without any complement, like "available":

	This is the only apartment available
	*This is the only apartment inexpensive

Mv and Mg: Participle Modifiers
Mv connects nouns with passive participles:

             +--Mv-+
	     |     |       
	The dog chased by the man died

Mg connects nouns with present participles:

             +--Mg-+
             |     |
	The dog chasing the man died

These are sometimes known as "participle modifiers". Every
passive verb form has a Mv-, directly disjoined with its Pv-
(used in normal passive constructions). Every present
participle has an Mg-, directly disjoined with Pg- (used in
normal present participle constructions). Thus in complex
verbs, whatever complement is normally required or allowed by
the participle (O+, TH+, TO+, etc.) will be required or
allowed here. (Passive verb-forms have different complement
expressions from active forms; see "Pv".)

	The dog chased by the man was black
	*The dog chased the man was black
	*The dog chasing was black
	The dog chasing the man was black
	People expecting to see the President will be disappointed
	*People expecting will be disappointed

If Mv- is directly disjoined with Pv- in every case, and Mg-
with Pg-, why have two different connector types?  The reason
relates to post-processing. Post-processing divides a sentence
into groups of links, in which each group corresponds,
roughly, to a clause: the set of links involved in a
subject-verb expression (as well as any direct object,
indirect object, or prepositional phrases). If the clause
contains a embedded clause, this forms its own group. In some
cases that participles are used, they belong to the same
subject-verb expression as the previous links (ex. 1 below).
In cases of participle modifiers, however, the participle
indicates the beginning of a new subject-verb expression
(ex. 2). 

                                +----J----+
         +--D--+-S-+--Pv-+--MV--+   +--D--+
         |     |   |     |      |   |     |
	The study was mentioned in the journal

                                        +--J(e)--+
                        +-Mv(e)-+-MVp(e)+   +D(e)+
                        |       |       |   |    |
	I've read the study mentioned   in the journal

Thus Mg and Mv links must start new domains; Pv and Pg links
must not.

This distinction is particularly important in cases where we
use post-processing to enforce subject-verb constraints, such
as "filler" uses of "it" and "there". Post-processing must
know that in cases of participle modifiers, the verb in the
participle modifiers does not apply to the subject of the main
clause; thus it knows that "There seems to have been a study
mentioned in the journal" is correct, while "There seems to
have mentioned a study in the journal" is incorrect. See "SF:
Filler-it".

Mv+, Mg+ used on conjunctions
Some conjunctions can also take present and past participles
instead of noun-phrases and clauses: "We saw a movie ABOUT
CATCHING dogs", "We entered BY CLIMBING in the window",
"He will respond WHEN QUESTIONED". Mv and Mg are used
here to connect the conjunction to the participle. 

Again, the question arises here: why use Mg+ and Mv+ rather
than Pv+ and Pg+? This is a difficult question, and again,
relates only to post-processing.  Recall that Mg and Mv begin
new domains; they imply that a new subject is in force. In
many cases this seems to hold true with participles modifying
prepositions and conjunctions.  This is particularly true when
the preposition modifies a noun (ex. 1), but also sometimes
when it modifies a verb (ex. 2).

                         +---Mp-+---Mg-+
	                 |      |      |
     1.	We saw a great movie about catching dogs
	           
               +-------MVp---+-Mg---+
               |             |      |
     2. She criticized us   for   chasing the dog
     3.?There was a problem while catching the dog

In other cases, however, it seems that the previous subject is
still implied:

     4. We talked about catching dogs
     5. We angered her by chasing the dog
     6. The man died while chasing the dog

At the moment, this has little effect on well-formedness.
The only cases it matters are where post-processing checks are
used to control the uses of "there". If we used Pg connectors
rather than Mg, then sentences like ex. 3 above would be 
prohibited; perhaps they should be. In any case, for now,
Mg and Mv are used in all such cases. 

Mr: Possessive Relatives
Mr is used for relative clauses involving "whose":

	     +-Mr-+-Ds*w+-S--+
	     |    |     |    |
	the dog whose owner died was black

                        +---Bsm--+
             +-Mr-+-Ds*w+     +S-+
             |    |     |     |  |
	the dog whose owner John hit was black

The two constructions shown here are exactly analagous
to the uses of "whose" (and other question-determiners
like "which") in indirect questions. A combination of 
link logic and post-processing rules enforces very
tight constraints on the use of Ds#w and Bsm (and hence
of Mr as well); see "SI: Questions without s-v inversion",
"B: Object-type Questions".

Like Mg and Mv connectors and relative clauses (R+ & B+),
Mr connectors start a new domain. See Mg and Mv for an
explanation.

Mj: Prepositional-object relative clauses
Mj is used for relative clauses in which the main
noun is the object of a preposition: 

                  +---Cs--+
             +-Mj-+-Jw-+  |
             |    |    |  |
     1.	The man   to whom I was speaking was tall

                  +------Cs-----+
                  +----J----+   |
             +-Mj-+--JQ-+-D-+   |
             |    |     |   |   |
     2.	The man   to whose wife I was speaking was tall

The "JQ" and "Jw" links used here are also used in
prepositional questions ("To whom were you speaking"). See
"JQ"; see "Jw".

Prepositions have "Mj- & Cs+" conjoined with J+ (which forms
the "Jw" link with "whom"), and disjoined with "MVp- or Mp- or
(Wj- & Qd+)..." (used in prepositional questions).  This
raises possible problems. In relative constructions like the
above, the prepositional object used must be a relative
pronoun like "whom" (*The man to the man I was speaking was
tall", "*The man to John's wife I was speaking was tall".
Furthermore, we must prevent "whom" and "whose" being used in
any old way: "*I was speaking to whom", "*I was speaking to
whose wife".  These problems have been dealt with already in
connection with prepositional questions: e.g., "To whom were
you speaking?".  There, we have Wj - the link connecting the
preposition to the wall - start a domain whose group contains
only the initial prepositional phrase of the sentence; we then
require that every group containing a Wj contain a Jw or a JQ,
and that Jw and JQ may occur only in groups containing a
Wj. (see "JQ".) Here, then, all we have to do is add "Mj" to
the list of links that require JQ or Jw and satisfy the
requirement of JQ and Jw.  The same constraints that apply in
prepositional questions then automatically apply here.

Note that this system very naturally permits more nested
constructions like "The dog to the wife of whose owner you
were speaking is here".

M with "not"
The word "not" is sometimes used with noun-modifying phrases:
"Students not enrolled in the course must pay a fee", "Students
not taking the course for credit must pay a fee:.

    +-Mvn-+-Mv--+
    |     |     |
Students not enrolled in the course must pay a fee

Notice that the noun connects to the participle through the
word "not". The Mv- on "not" is subscripted simply to prevent it
from starting a domain. Similar constructions can be formed with
Mp, Ma, and Mg.

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