Please note: If no explicit feature declarations are given, in most cases,
they can be derived automatically from the corpus.Actually, corpora for TIGERSearch have to be defined in TIGER-XML. However, TIGER-XML is a direct translation of the corpus definition sublanguage of the TIGER description language. The restrictions for corpora are as follows:
Declaration of required features
A corpus definition must include the feature declarations for the type NT of nonterminal constraints and the type T of terminal constraints.
Please note: If no explicit feature declarations are given, in most cases,
they can be derived automatically from the corpus.
Single Root Node, Connectedness, No Structure Sharing
Every node in a graph except for one distinguished node (root node) has to be directly dominated by exactly one other node.
Please note: A multi-rooted graph (unconnected subgraphs) can be turned
automatically into a graph with unique root node by adding an
'artificial' root node plus the edges which point to the
individual subgraphs.
Please note: A structure sharing mechanism (multi-dominance) is provided by
the additional layer of 'secondary edges'.
Acyclicity
No node may (indirectly) dominate itself.
Full Disambiguation
The graph constraints may only include the basic node
relations labelled direct dominance (>L) and direct
precedence (.).
The feature constraint for a node must be a conjunction of
feature-value pairs either for all features which have been
declared for NT or for those which have been defined
for T.
For each node, its arity (i.e. the number of its children)
has to be fixed.
The precedence relation on terminal nodes (leaf nodes) must
be a total order.
The only logical connective on all structural levels is the
conjunction operator &.
Neither types nor template calls nor regular expressions are
admitted.