L connects certain determiners to superlative adjectives. 

	       +------D----+
	       +--L--+     |
               |     |     |
       He has the biggest room

In most cases, when a determiner-adjective-noun phrase occurs,
both the determiner and the adjective attach to the noun.
Superlative adjectives are different, however.  Superlatives
must be used with determiners, and only certain determiners:

	This is their biggest room
	*This is a biggest room
	*They have biggest rooms
	
To enforce this, it seems easiest to simply make the
superlative connect to the determiner. Determiners that can
perform this function carry "{L+} & D+". Superlative
adjectives carry "L-".

As well as superlatives, other adjectives are in this category
such as "own", "next", and "same".  Number words like "third"
and "fifteenth" are also included: "This is the fifteenth book
I've read", "*This is a fifteenth book I've read", "*This is
fifteenth book I've read".

Numbers can also be used here, on the left end of an L link:
"The five biggest cities are in China". As in other cases with
determiners followed by numbers ("The five cities we saw
were..."), the DD link is used: numbers thus carry "{{L+} &
DD-} & (Dmc+ or S+...)".

              +------Dmc----+
         +-DD-+--L--+       +-S--+
	 |    |     |       |    |
	The five biggest cities are

Note that the L+ on numbers is conjoined with the DD-; it may
not be used unless the DD- is used. This prevents "*Five
biggest cities are in China".

On determiners that take L+, it is conjoined not only with D+
but with DD+. This allows "The biggest five cities..."

The indirect article "a" cannot connect with superlatives
("*That is a best movie"); they do sometimes connect with
number terms like first and third ("A third reason for doing
it"...). Thus we give "a/an" Lf+; superlatives get La-, to
prevent the two from connecting.