S-rule

Revision as of 10:55, 23 March 2010

S-rule (syntactic rule) is the formalism used for describing syntactic structures and syntactic operations in the UNL^arium framework.

When to use S-rules

S-rules are used for:

• creating compounds out of the base forms (such as "take">"take into account");
• generating complex grammar structures (such as "love">"will love");
• defining syntactic roles (such as "subject", "object", etc);
• defining dependency relations (such as agreement);
• defining the distribution (i.e., order and adjacency) of word forms; and
• projecting syntactic structures out of the constituents.

When not to use S-rules

S-rules are not used for for affixation (prefixation, infixation, suffixation) or spelling changes, which must be addressed by A-rules and Ph-rules, respectively.

Types of S-rules

There are four types of S-rules:

• Head extension extends a given head.
• Specification creates a specifier (determiner) to the head;
• Complementation creates a complement (object) to the head;
• Adjunction creates an adjunct (modifier) to the head; and

Syntax

S-rules comply with the following syntax:

CONDITION := RELATION(HEAD; ARGUMENT);

Where

• CONDITION (optional) is a tag or list of tags, extracted from the UNDLF Tagset, that indicates when the rule should be applied, and that it's to be omitted if always applied. The CONDITION may also be a relation or a list of relations in case of projection rules.
• RELATION is the syntactic relation, extracted from the syntactic roles, between the head and its argument. An S-rule may comprise several different relations, to be separated by ",".
• HEAD (optional) is the head of the syntactic structure, which is to be omitted when does not undergo any change;
• ARGUMENT (optional in case of head-only relations) is the argument (the specifier, the complement or the adjunct) of the head.

The HEAD and the ARGUMENT may be expressed as:

• a "string" (strings must come between parentheses);
• a [lemma] (lemmas must come between square brackets);
• a feature or a set of features, separated by comma, and extracted from the the UNDLF Tagset;
• a direction (">",">>","<","<<");
• a variable (to be specified both in the left and in the right side of the rule by the syntax %name);
• an action, to be performed through an A-rule; and
• a syntactic relation itself.

Examples

Examples of S-rules:

• word-formation
  • VA("into account"); (add the string "into account" as the adjunct of the verb)
• compound tenses:
  • FUT:=IH([will]); (add the lemma "will" as the head of the inflectional phrase in case of future)
• government
  • VC(PP([in])); (the complement of the verb must be introduced by the preposition "in")
• agreement
  • VS(ANUM,APER); (the specifier of the verb assigns number (ANUM) and person (APER) to its head
• distribution
  • VA(>>); (the adjunct of the verb comes at the right side after a blank space)
• projection
  • VS(%head;%spec)VB(%head;%comp):=VP(VB(%head;%comp);%spec); (integrate the two relations on the left side into a single relation)