C-rule

Revision as of 19:16, 8 December 2011

Compounding or composition is the word-formation process of creating compounds by combining or putting together lexemes. This process is performed by Composition rules (CPWR), which are used to generate compounds out of the base form.

When to use composition rules

In the UNL^arium framework, compounds are treated as ordinary simple words except in case of discontinuous multiword expressions or with infixation (such as "give in" or "take into account"). In these cases, the lemma is different from the base form, and the compound-formation process is expected to be defined through special rules.
Composition rules must be created when and only when the base form is different from the lemma.
This situation occurs only in case of the following multiword expressions:

• when inflections are formed by infixation (in opposition to simple suffixation or prefixation); or
• when the multiword expression is discontinuous.

For instance:
The English multiword expression "call for" has the following inflections: "call for", "calls for", "called for", "calling for", etc. These inflections are formed by infixation, in the sense they apply in the middle of the expression (between "call" and "for"). If we simply associate this expression to the inflectional paradigm of "call", we will have the following results: "call for", "call fors", "call fored", "call foring", etc. In order to prevent this problem, and to avoid the unnecessary proliferation of rules in the grammar, we split the multiword expression into two segments: the base form (BF), i.e., the term over which the inflections will be directly applied; and the composition rule (CPWR), which is the rule used to rebuild the lemma out of the base form. In the case of "call for", the lemma is "call" and the composition rule is "VH([for],P,M0);".

When not to use composition rules

Composition rules must not be used in the following circumstances:

• When the word is not a multiword expression;
• When the multiword expression is invariant;
• When the inflections of the multiword expression are formed by prefixation or suffixation (such as in "call center" > "call centers");

Examples

Syntax

The syntax for composition rules is the following:

<SYNTACTIC ROLE>(<ADDED>,<FEATURES);

Where:

• <SYNTACTIC ROLE> is the syntactic role (VA, VC, VS, VH, etc) of the term to be added to the base form;
• <ADDED> is the term to be added to the base form to form the compound. It must be represented between [brackets], if it is a lemma (i.e., if it is an entry in the dictionary), or between "quotes", if a string (i.e., if it is not an entry in the dictionary)
• <FEATURES> are the features of the term to be added to the base form. The following features are mandatory:
  • the lexical category (A,J,N,V,C,P,D) of the term to be added
  • the inflectional properties (paradigm and/or inflectional rules) of the term to be added
  • the distribution (i.e., the position) of the term to be added, if not default
  • the adjacency of the term to be added, if not default

There can be several different composition rules associated to the same base form in order to form complex expressions such as "give up the ghost", where there are at least three constituents: "give", which is the base form; and "up" and "the ghost", which will part of different composition rules:

• VH([up],P,M0);VC("the ghost",N,M0);

Composition rules in the dictionary

In the UNL^arium framework, composition rules may be expressed in two different formats:

• As complex structures, such as^[1]

[[sub-NLW][sub-NLW]...[sub-NLW]]  {ID}  “UW”  (ATTR , ..., #01(ATTR, ...), #02(ATTR, ...), ...)  < FLG , FRE , PRI >; COMMENTS

• As simple structures, such as

[NLW]  {ID}  “UW”  (ATTR , ..., BF=<BASE FORM>, CPWR=MTW(<COMPOSITION RULE>) )  < FLG , FRE , PRI >; COMMENTS

Where <COMPOSITION RULE> is the rule or set of composition rules used to form the lemma out of the base form, and <BASE FORM> is the base form. Notice that the compostion rule must be informed as a value of the attribute CPWR and should be preceded by the multiword tag MTW because there can be several different composition rules associated to the same entry.

Example of dictionary entries containing composition rules

• [[bring] [back]] {12343} "202078294" (pos=VER, #01(IFX(ET0:=4>"ought")), #02(pos=PRE)) <eng, 0, 0>;
• [bring back] {12343} "202078294" (pos=VER, BF=bring, CPWR=MTW(VA([back],A,M0);)) <eng, 0, 0>;

Observations

Phrasal verbs

Particles of phrasal verbs must be represented as part of the head, if non separable, or as adjuncts, if separable:

• give in = VH([in]); ("give in something" but "give something in")
• give back = VA([back]); ("give back something" or "give something back")

General syntactic roles (NP, PP, XP) must not be defined in composition rules but inside the subcategorization frame

• throw <person> to the lions =+VA("to the lions"); (and not "VA("to the lions")VC(NP);". The lemma should be associated to the transitive frame instead)

"Quotes" or [brackets]?

In the compound-formation process, the UNL^arium distinguishes between strings (to be represented between "") and lemmas (to be represented between [ ]). The difference between strings and lemmas has to do with the dictionary status: lemmas (but not strings) are expected to be dictionary entries.

• VA("into account"); (the string "into account" is not expected to be a dictionary entry)
• VC([sense]); (the term "sense" is expected to be a dictionary entry).

Complex compounds

Compounds must include as many terms as different syntactic roles. One single "+" must be provided at the beginning of the rule:

• give up the ghost = VH([up])VC("the ghost"); (+VH("up the ghost") or +VC("up the ghost"))

Order is to be represented by the distribution features (">", ">>", "<", "<<", ...), if not default

• VC([love]); (order must not be informed, because in English complements come at the right side by default: make > make love)
• NS([the]); (order must not be informed, because in English specifiers come at the left side, by default: Netherlands > the Netherlands)
• NA(>>,[available]); (order must be informed, because in English nominal adjuncts come at the left side, by default: table > new table)

Adjacency is to be represented by the adjacency features (AJ0,AJ1,AJ2,...), if not default

• VC([love]); (adjacency must not be informed, because in English complements come after the head, by default: make > make love)
• VH([up])VC("the ghost"); (adjacency must not be informed, because in English head particles come before complements, by default: give > give up the ghost)
• VA([home],AJ1)VC("the bacon",AJ2); (adjacency must be informed because in English the complement is normally generated before the adjunct: bring the bacon home)

Notes

1. ↑ For further information on complex structures inside the dictionary, refer to Dictionary Specs#Complex structures as NLW*