Grammar Specs

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Revision as of 20:08, 16 August 2013

The following Grammar Specs are used for writing rules for the UNDL Foundation tools (IAN, EUGENE, SEAN, NORMA, etc.).

Basic symbols used in the UNL framework
Symbol	Definition	Example
( )	node	(%a)
" "	string	"went"
[ ]	natural language entry (headword)	[go]
[[ ]]	UW	[[to go(icl>to move)]]
//	regular expression	/a{2,3}/ = aa,aaa
rel(x;y)	relation	agt(kill;Peter)
^	not	^a = not a
{ \| }	or	{a\|b} = a or b
%	index for nodes, attributes and values	%x
:	scope ID	:01
#	index for sub-NLWs	#01
=	attribute-value assignment	POS=NOU
!	rule trigger	!PLR
&	merge operator	%x&%y
?	dictionary lookup operator	?[a]

[file:grammar.png]

Node: A node is the most elementary unit in the graph. It is the result of the tokenization process, and corresponds to the notion of "lexical item". At the surface level, a natural language sentence is considered a list of nodes, and a UNL graph a set of relations between nodes.
Relation: In order to form a natural language sentence or a UNL graph, nodes are inter-related by relations. In the UNL framework, there can be three different types of relations: linear, syntactic or semantic.
Hyper-Node: A hyper-node is a sub-graph, i.e., a node containing relations between nodes.
Hyper-Relation: A hyper-relation is a relation between relations.

@@ Line 5: / Line 5: @@
 == Basic Concepts ==
+[file:grammar.png]
 ;[[Node]]
 :A node is the most elementary unit in the graph. It is the result of the [[tokenization]] process, and corresponds to the notion of "lexical item". At the surface level, a natural language sentence is considered a list of nodes, and a UNL graph a set of relations between nodes.