ALE Keyword Summary

The following is a summary of keywords discussed in this manual, along with page references. A table of auxiliary keywords, those that only occur as arguments of other keyword operators, such as the cat> argument of a rule, will be provided in a future version.

A keyword of kind Description is one that occurs in an ALE description of a feature structure. One of kind Def. Clause, or DCL, is one that occurs in ALE's definite clause language. One of kind Signature is a declaration that occurs in an ALE signature. One of kind Type is an ALE type with special properties. One of kind ALE is a Prolog query (entered at the | ?- prompt) that can be used after ALE has been loaded (see p. ). One of kind Mini-interpreter is a mini-interpreter command that appears in an interpreter action-line. One of kind Debugger is a Prolog query that can be used after the source-level debugger has been loaded. For debugger responses, the reader is referred to the table on page .

Keyword	Kind	Description	Page
,	Desc./DCL	Conjunction	,
-->	Signature	Declare lexical entry.
-> (;)	Def. Clause	Shallow cut.
:	Description	Feature value.
;	Desc./DCL	Disjunction.	,
!	Def. Clause	Cut.
\+	Def. Clause	Negation-by-failure.
==	Description	Path Equation.
=@	Def. Clause	Predefined token-identity definite clause predicate.
=\=	Description	Inequation.
@	Description	Macro instantiation.
[$\ldots$]	Description	Predefined list macro.
%	Prolog	Comment delimiter.

Keyword	Kind	Description	Page
a_	Description/Signature	Built-in extensional atom.
abort	Mini-interpreter	Abort parse.
add	Mini-interpreter	Add the current edge.
approp	ALE	Show value restriction on a feature at a type.
assert	Prolog	Add clause to Prolog database.
bot	Type	In an ALE signature, this type must appear, and must subsume all of the other types.
break	Mini-interpreter	Invoke Prolog break.
chain_length	ALE	Set limit on chain rule sequence length.
compile_gram	ALE	Compile ALE signature (or parts of it -- see table, p. ).
compile	Prolog	Compile a Prolog file.
cons	Signature	Declare type constraint.	,
consult	Prolog	Load Prolog file (such as an ALE signature) into database.
continue	Mini-interpreter	Proceed to look for more (subsuming/subsumed) edges.	,
control-c	Prolog	Prolog interrupt.
control-z	Unix	Unix interrupt.
dclear_bps	Debugger	Clear all breakpoints in current grammar file.
dcompile_gram	Debugger	Compile grammar file for source-level debugging.
dgen	Debugger	Generate with source-level debugger.
dleash	Debugger	Set or remove leashing on a kind of step.
dquery	Debugger	Evaluate a definite clause with source-level debugging.
drec	Debugger	Parse with source-level debugger.
dskip	Debugger	Set or remove auto-skipping on a kind of step.
dtr-N	Mini-interpreter	Display Nth daughter edge of current edge.
edge	ALE	Show a chart edge.
emacs	Debugger	Turn on XEmacs interface to source-level debugger.
empty	ALE	Show empty categories.
empty	Signature	Declare empty category.
export_words	ALE	Send list of words in lexicon to stream
existing	Mini-interpreter	Display edge that subsumes new feature structure.
ext	Signature	Declare extensional types.
feature	ALE	Test if feature exists.
generate	ALE	Tell compiler to produce code for generation only.

Keyword	Kind	Description	Page
gen	ALE	Generate a string using the compiled generator.	,
go	Mini-interpreter	Add current and all subsequent edges.
go-N	Mini-interpreter	Add current and all subsequent edges until node N is reached.
halt	Prolog	Exit from Prolog.
if	Def. Clause	Definite clause language equivalent of :-.
incoming	Mini-interpreter	Display incoming edge that subsumes existing edge.
interp	ALE	Turn on mini-interpreter.
intro	Signature	Declare appropriate features for type.
introduce	ALE	Test if a feature was introduced by a type.
iso_desc/2	ALE	Test whether two descriptions evaluate to the same feature structure.
lex	ALE	Show lexical entry.
lex_compile	ALE	Compile lexicon intermediate code (SICStus only)
lex_consult	ALE	Dynamically consult lexicon intermediate code
lex_rule	ALE	Show lexical rule.
lex_rule	Signature	Declare lexical rule.
lex_rule_depth	ALE	Set bound on lexical rule application.
list	Type	This type, along with types e_list and ne_list, and features HD and TL, must be defined in an ALE signature in order to use the predefined [$\ldots$] macro in descriptions, or the cats> list-argument operator in grammatical rules.	,
macro	ALE	Show macro definition.
macro	Signature	Declare macro.
mgsat	ALE	Find most general satisfier(s) of a type.
no_write_feat	ALE	Hide a feature and its value.
no_write_type	ALE	Hide a type.
noadd	Mini-interpreter	Do not add the current edge.
noemacs	Debugger	Turn off XEmacs interface to source-level debugger.
nointerp	ALE	Turn off mini-interpreter.
nosubtest	ALE	Disable edge subsumption checking.
parent	Mini-interpreter	Return to parent edge.
parse	ALE	Tell compiler to produce code for parsing only.

Keyword	Kind	Description	Page
parse_and_gen	ALE	Tell compiler to produce code for parsing and generation.
prolog	Def. Clause	Definite clause hook to Prolog.
query	ALE	Evaluate a definite clause.
rec	ALE	Parse a string.	,-
rec_best	ALE	Parse first parsable string in a list of strings
rec_list	ALE	Parse a list of strings	,
retract	Mini-interpreter	Retract currently displayed edge.
retract	Prolog	Remove clause from Prolog database.
retractall_lex	ALE	Retract all of a word's entries from lexicon
retract_lex	ALE	Retract a word's entry from lexicon
rule	ALE	Show grammatical rule.
rule	Signature	Declare grammatical rule.
semantics	ALE	Declares a semantics definite clause predicate.
show_clause	ALE	Show a definite clause.
show_cons	ALE	Show constraint for a type.
show_type	ALE	Show subtypes, supertypes, constraint and most general satisfiers for a type.
sub	Signature	Declare subtyping relationship.
subtest	ALE	Enable edge subsumption checking, and, if necessary, compile code for it.
sub_type	ALE	Test subsumption between two types.
true	Def. Clause	Definite clause that is always satified (also used to construct ground clauses in def. clause language).
type	ALE	Test if type exists.
unify_type	ALE	Unify two types.
update_lex	ALE	Add new entries to lexicon
when	Def. Clause	Co-routining
write_feat	ALE	Don't hide a feature.
write_feats	ALE	Don't hide any features.
write_type	ALE	Don't hide a type.
write_types	ALE	Don't hide any types.