Editing Link grammar (section)

=== Example 4 (phonology) ===
The link-grammar can also indicate [[Phonology|phonological agreement]] between neighboring words. For example:

                      +---------Ost--------+
     +------>WV------>+   +------Ds**x-----+
     +----Wd---+-Ss*b-+   +--PHv-+----A----+
     |         |      |   |      |         |
 LEFT-WALL that.j-p is.v an abstract.a concept.n

Here, the connector 'PH' is used to constrain the determiners that can appear before the word 'abstract'. It effectively blocks (makes it costly) to use the determiner 'a' in this sentence, while the link to 'an' becomes cheap.  The other links are roughly as in previous examples: S denoting subject, O denoting object, D denoting determiner. The 'WV' link indicates the head verb, and the 'W' link indicates the head noun.  The lower-case letters following the upper-case link types serve to refine the type; so for example, Ds can only connect to a singular noun; Ss only to a singular subject, Os to a singular object.  The lower-case v in PHv denotes 'vowel'; the lower-case d in Wd denotes a declarative sentence.