Creating a Grammar
The grammar of a project consists of phrase structure rules, the definition of any variables
used to describe the phrase structure rules, the specification of lexical categories and a lexicon.
Specifying a grammar allows the user to draw trees in the assisted draw mode as well as using the check tree operation.
The operations to maintain the grammar for a project can be found under the Grammar menu heading and include
Set up Rules and Set up Lexicon.
Maintaining phrase structure rules
Phrase structure rules can be maintained by choosing Grammar|Set up Rules.
This will open the Set up Rules dialog, which will allow the user to add, edit, and delete phrase structure rules.
Changes to the rules will be automatically reflected on the Grammar Pane.
The order that the rules are displayed in the grammar pane can also be set via this dialog.
Adding rules
Rules are added to the grammar by pressing the Add button, which will open an Add Rule dialog prompting the user for the
new rule.
The format for a rule consists of a head category followed by a "consists of" symbol (written as "->") followed by the elements
that make up the head category.
Optionality is specified with parenthesis ( ) around the optional elements.
Repeated elements are indicated with a "+". Choices are indicated by surrounding the choices with curly brackets { } and separating each
choice with a "|". Square brackets [ ] can be used for grouping if necessary.
Non-category specific rules can also be added by making use of variables.
For example the X in the above XP -> XP conj XP rule where X can stand for any category N, V, A, P.
This provides a convenient means for adding conjunction to the grammar, as in the above case, and for allowing the
specification of X' theory.
It is also possible to add more than one rule with the same head category which also provides
support for the specification of X' theory.
Editing rules
Rules are edited by selecting the rule and pressing the Edit button, which will open an Edit Rule dialog prompting the user for the
changed rule.
Removing rules
Rules are removed by selecting the rule and pressing the Remove button, which will remove the rule from the grammar.
Ordering rules
Rules are ordered by selecting a rule and pressing either the move up or move down button.
Maintaining variables
Variables are used to allow for the specification of X' theory and to provide a convenient means for adding conjunction to the
grammar. They allow the user to specify a rule which is non-category specific, such as X -> X conj X where X can stand for any
category. For assisted draw and the check tree operation to run correctly, it is necessary for the user to indicate that X is,
in fact, a variable and to specify which categories X can stand for.
Variables can be maintained by choosing Grammar|Set up Rules.
This will open the Set up Rules dialog that will allow the user to add, edit, and delete variables.
Changes to the variables will be automatically reflected on the Grammar Pane.
The order that the variables are displayed in the grammar pane can also be set via this dialog.
Adding variables
Variables are added to the grammar by pressing the Add button, which will open an Add Variable dialog prompting the user for the
new variable definition.
The format for a variable definition consists of the variable followed by a "consists of" symbol (written as "->") followed by the possible
categories that make up the variable. The possible categories are surrounded with curly brackets { } and each category is separated
with a "|".
Editing variables
Variables are edited by selecting the variable and pressing the Edit button, which will open an Edit Variable dialog prompting the user for the
changed variable definition.
Removing variables
Variables are removed by selecting the variable and pressing the Remove button, which will remove the variable from the grammar.
Ordering variables
Variables are ordered by selecting a variable and pressing either the move up or move down button.
Maintaining Lexical Categories
Lexical Categories are the categories that constitute the parts of speach (N, V, A, P, T, C etc...).
For assisted draw and the check tree operation to run correctly, the program must know which categories are lexical categories.
By default, the program will assume that any category listed in the phrase structure rules, that is not the head of a rule, is a
lexical category (and, therefore, must be terminated with a word). However, if a rule is added in which a word-level category
is the head, such as a conjunction rule
(i.e. X -> X conj X or N -> N conj N), then the user must specify that these categories are lexical categories. If variables are used
to represent the categories, then this can be done by entering the variable.
Lexical Categories can be maintained by choosing Grammar|Set up Rules.
This will open the Set up Rules dialog that will allow the user to add, edit, and delete lexical categories.
Adding lexical categories
Lexical Categories are added to the grammar by pressing the Add button, which will open an Add Lexical Category dialog
prompting the user for the new lexical category.
The format for a lexical category consists of the name of that category or a variable representing a number of categories.
Editing lexical categories
Lexical Categories are edited by selecting the lexical category and pressing the Edit button, which will open an
Edit Lexical Category dialog prompting the user for the new category name.
Removing lexical categories
Lexical Categories are removed by selecting the lexical category and pressing the Remove button, which will remove
the lexical category from the grammar.
Ordering variables
Lexical Categories are ordered by selecting a lexical category and pressing either the move up or move down button.
Maintaining the lexicon
The lexicon can be maintained by choosing Grammar|Set up Lexicon.
This will open the Set up Lexicon dialog that will allow the user to add, edit, and delete lexicon entries.
Changes to the lexicon will be automatically reflected on the Grammar Pane.
Adding lexicon entries
Lexicon entries are added to the grammar by pressing the Add button, which will create a blank row in the table allowing the user to
enter the new lexicon entry.
The possible categories are restricted to a drop down list consisting of categories, in the phrase structure rules, which are either
not the head of any rule or have been specified as lexical categories.
It is also possible to add more than one entry with the same word but a different category.
Editing lexicon entries
Lexicon entries are edited directly in the table by changing the word and/or selecting a different category.
Removing lexicon entries
Lexicon entries are removed by selecting a row and pressing the Remove button, which will remove the entry from the lexicon.
Ordering lexicon entries
The order that the lexicon entries are displayed in the lexicon tab can be controlled by clicking on a particular column header
to sort the entries based on this column. A repeated click on the same column header changes the sort order direction from
ascending to descending and vice versa. The columns can also be resized by the user.