S-rule

Revision as of 20:00, 22 March 2010

S-rule (syntactic rule) is the formalism used for describing syntactic hierarchies 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 are dealt 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, or a relation or list relations, that indicates when the rule should be applied, and that it's to be omitted if always applied;
• RELATION is the syntactic relation, extracted from the syntactic roles, between the head and its argument;
• 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 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 phrase (NP, VP, PP, etc), extracted from the syntactic roles;
• 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

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)
• 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);