Provided by: latexml_0.7.0-1_all bug


       "LaTeXML::Package" - Support for package implementations and document customization.


       This package defines and exports most of the procedures users will need to customize or
       extend LaTeXML. The LaTeXML implementation of some package might look something like the
       following, but see the installed "LaTeXML/Package" directory for realistic examples.

         use LaTeXML::Package;
         use strict;
         # Load "anotherpackage"
         # A simple macro, just like in TeX
         DefMacro('\thesection', '\thechapter.\roman{section}');
         # A constructor defines how a control sequence generates XML:
         DefConstructor('\thanks{}', "<ltx:thanks>#1</ltx:thanks>");
         # And a simple environment ...
         # A math  symbol \Real to stand for the Reals:
         DefMath('\Real', "\x{211D}", role=>'ID');
         # Or a semantic floor:
         # More esoteric ...
         # Use a RelaxNG schema
         # Or use a special DocType if you have to:
         # DocType("rootelement",
         #         "-//Your Site//Your DocType",'your.dtd',
         #          prefix=>"http://whatever/");
         # Allow sometag elements to be automatically closed if needed
         Tag('prefix:sometag', autoClose=>1);
         # Don't forget this, so perl knows the package loaded.


       To provide a LaTeXML-specific version of a LaTeX package "mypackage.sty" or class
       "myclass.cls" (so that eg. "\usepackage{mypackage}" works), you create the file
       "mypackage.sty.ltxml" or "myclass.cls.ltxml" and save it in the searchpath (current
       directory, or one of the directories given to the --path option, or possibly added to the
       variable SEARCHPATHS).  Similarly, to provide document-specific customization for, say,
       "mydoc.tex", you would create the file "mydoc.latexml" (typically in the same directory).
       However,  in the first cases, "mypackage.sty.ltxml" are loaded instead of "mypackage.sty",
       while a file like "mydoc.latexml" is loaded in addition to "mydoc.tex".  In either case,
       you'll "use LaTeXML::Package;" to import the various declarations and defining forms that
       allow you to specify what should be done with various control sequences, whether there is
       special treatment of certain document elements, and so forth.  Using "LaTeXML::Package"
       also imports the functions and variables defined in LaTeXML::Global, so see that
       documentation as well.

       Since LaTeXML attempts to mimic TeX, a familiarity with TeX's processing model is also
       helpful.  Additionally, it is often useful, when implementing non-trivial behaviour, to
       think TeX-like.

       Many of the following forms take code references as arguments or options.  That is, either
       a reference to a defined sub, "\&somesub", or an anonymous function sub { ... }.  To
       document these cases, and the arguments that are passed in each case, we'll use a notation
       like CODE($token,..).

   Control Sequences
       Many of the following forms define the behaviour of control sequences.  In TeX you'll
       typically only define macros. In LaTeXML, we're effectively redefining TeX itself,  so we
       define macros as well as primitives, registers, constructors and environments.  These
       define the behaviour of these commands when processed during the various phases of LaTeX's
       immitation of TeX's digestive tract.

       The first argument to each of these defining forms ("DefMacro", "DefPrimive", etc) is a
       prototype consisting of the control sequence being defined along with the specification of
       parameters required by the control sequence.  Each parameter describes how to parse tokens
       following the control sequence into arguments or how to delimit them.  To simplify coding
       and capture common idioms in TeX/LaTeX programming, latexml's parameter specifications are
       more expressive than TeX's  "\def" or LaTeX's "\newcommand".  Examples of the prototypes
       for familiar TeX or LaTeX control sequences are:

          DefPrimitive('\multiply Variable SkipKeyword:by Number',..
          DefPrimitive('\newcommand OptionalMatch:* {Token}[][]{}', ...

       Control Sequence Parameters

       The general syntax for parameter for a control sequence is something like

         OpenDelim? Modifier? Type (: value (| value)* )? CloseDelim?

       The enclosing delimiters, if any, are either {} or [], affect the way the argument is
       delimited.  With {}, a regular TeX argument (token or sequence balanced by braces) is read
       before parsing according to the type (if needed).  With [], a LaTeX optional argument is
       read, delimited by (non-nested) square brackets.

       The modifier can be either "Optional" or "Skip", allowing the argument to be optional. For
       "Skip", no argument is contributed to the argument list.

       The shorthands {} and [] default the type to "Plain" and reads a normal TeX argument or
       LaTeX default argument.

       The predefined argument types are as follows.

       "Plain", "Semiverbatim"
           Reads a standard TeX argument being either the next token, or if the next token is an
           {, the balanced token list.  In the case of "Semiverbatim", many catcodes are
           disabled, which is handy for URL's, labels and similar.

       "Token", "XToken"
           Read a single TeX Token.  For "XToken", if the next token is expandable, it is
           repeatedly expanded until an unexpandable token remains, which is returned.

       "Number", "Dimension", "Glue" or "MuGlue"
           Read an Object corresponding to Number, Dimension, Glue or MuGlue, using TeX's rules
           for parsing these objects.

           Reads tokens until a match to the tokens match is found, returning the tokens
           preceding the match.  This corresponds to TeX delimited arguments.

           Reads tokens until the next open brace "{".  This corresponds to the peculiar TeX
           construct "\def\foo#{...".

       "Match:"match(|match)*, "Keyword:"match(|match)*
           Reads tokens expecting a match to one of the token lists match, returning the one that
           matches, or undef.  For "Keyword", case and catcode of the matches are ignored.
           Additionally, any leading spaces are skipped.

           Read tokens until a closing }, but respecting nested {} pairs.

           Reads a token, expanding if necessary, and expects a control sequence naming a
           writable register.  If such is found, it returns an array of the corresponding
           definition object, and any arguments required by that definition.

           Skips any space tokens, but contributes nothing to the argument list.

       Control of Scoping

       Most defining commands accept an option to control how the definition is stored,
       "scope=>$scope", where $scope can be c<'global'> for global definitions, 'local', to be
       stored in the current stack frame, or a string naming a scope.  A scope saves a set of
       definitions and values that can be activated at a later time.

       Particularly interesting forms of scope are those that get automatically activated upon
       changes of counter and label.  For example, definitions that have "scope=>'section:1.1'"
       will be activated when the section number is "1.1", and will be deactivated when the
       section ends.


       "DefMacro($prototype,$string | $tokens | $code,%options);"
           Defines the macro expansion for $prototype.  If a $string is supplied, it will be
           tokenized at definition time, and any macro arguments will be substituted for
           parameter indicators (eg #1) at expansion time; the result is used as the expansion of
           the control sequence.  The only option, other than "scope", is "isConditional" which
           should be true, for conditional control sequences (TeX uses these to keep track of
           conditional nesting when skipping to \else or \fi).

           If defined by $code, the form is "CODE($gullet,@args)" and it must return a list of

       "DefMacroI($cs,$paramlist,$string | $tokens | $code,%options);"
           Internal form of "DefMacro" where the control sequence and parameter list have already
           been parsed; useful for definitions from within code.  Also, slightly more efficient
           for macros with no arguments (use "undef" for $paramlist).


           Define a primitive control sequence.  These are usually done for side effect and so
           CODE should end with "return;", but can also return a list of digested items.

           The only option is for the special case: "isPrefix=>1" is used for assignment prefixes
           (like \global).

           Internal form of "DefPrimitive" where the control sequence and parameter list have
           already been parsed; useful for definitions from within code.

           Defines a register with the given initial value (a Number, Dimension, Glue, MuGlue or
           Tokens --- I haven't handled Box's yet).  Usually, the $prototype is just the control
           sequence, but registers are also handled by prototypes like "\count{Number}".
           "DefRegister" arranges that the register value can be accessed when a numeric,
           dimension, ... value is being read, and also defines the control sequence for

           Options are

               specifies if it is not allowed to change this value.

           "getter"=>CODE(@args) =item "setter"=>CODE($value,@args)
               By default the value is stored in the State's Value table under a name
               concatenating the control sequence and argument values.  These options allow other
               means of fetching and storing the value.

           Internal form of "DefRegister" where the control sequence and parameter list have
           already been parsed; useful for definitions from within code.


       "DefConstructor($prototype,$xmlpattern | $code,%options);"
           The Constructor is where LaTeXML really starts getting interesting; invoking the
           control sequence will generate an arbitrary XML fragment in the document tree.  More
           specifically: during digestion, the arguments will be read and digested, creating a
           LaTeXML::Whatsit to represent the object. During absorbtion by the LaTeXML::Document,
           the "Whatsit" will generate the XML fragment according to the replacement $xmlpattern,
           or by executing "CODE".

           The $xmlpattern is simply a bit of XML as a string with certain substitutions to be
           made.  The substitutions are of the following forms:

           If code is supplied,  the form is "CODE($document,@args,%properties)"

           #1, #2 ... #name
               These are replaced by the corresponding argument (for #1) or property (for #name)
               stored with the Whatsit. Each are turned into a string when it appears as in an
               attribute position, or recursively processed when it appears as content.

               Another form of substituted value is prefixed with "&" which invokes a function.
               For example, " &func(#1) " would invoke the function "func" on the first argument
               to the control sequence; what it returns will be inserted into the document.

           "?COND(pattern)"  or "?COND(ifpattern)(elsepattern)"
               Patterns can be conditionallized using this form.  The "COND" is any of the above
               expressions, considered true if the result is non-empty.  Thus "?#1(<foo/>)" would
               add the empty element "foo" if the first argument were given.

           "^" If the constuctor begins with "^", the XML fragment is allowed to float up to a
               parent node that is allowed to contain it, according to the Document Type.

           The Whatsit property "font" is defined by default.  Additional properties "body" and
           "trailer" are defined when "captureBody" is true, or for environments.  By using
           "$whatsit->setProperty(key=>$value);" within "afterDigest", or by using the
           "properties" option, other properties can be added.

           DefConstructor options are

               Changes to this mode during digestion.

               If true, TeX grouping (ie. "{}") is enforced around this invocation.

               These specify whether the given constructor can only appear, or cannot appear, in
               math mode.

               Specifies the font to be set by this invocation.  See "MergeFont" If the font
               change is to only apply to this construct, you would also use "<bounded="1>>.

           reversion=>$texstring or CODE($whatsit,#1,#2,...)
               Specifies the reversion of the invocation back into TeX tokens (if the default
               reversion is not appropriate).  The $textstring string can include #1,#2...  The
               CODE is called with the $whatsit and digested arguments.

           properties=>{prop=>value,...} or CODE($stomach,#1,#2...)
               This option supplies additional properties to be set on the generated Whatsit.  In
               the first form, the values can be of any type, but (1) if it is a code references,
               it takes the same args ($stomach,#1,#2,...) and should return a value.  and (2) if
               the value is a string, occurances of #1 (etc) are replaced by the corresponding
               argument.  In the second form, the code should return a hash of properties.

               This option supplies a Daemon to be executed during digestion just before the
               Whatsit is created.  The CODE should either return nothing (return;) or a list of
               digested items (Box's,List,Whatsit).  It can thus change the State and/or add to
               the digested output.

               This option supplies a Daemon to be executed during digestion just after the
               Whatsit is created. it should either return nothing (return;) or digested items.
               It can thus change the State, modify the Whatsit, and/or add to the digested

               Supplies CODE to execute before constructing the XML (generated by $replacement).

               Supplies CODE to execute after constructing the XML.

           captureBody=>boolean or Token
               if true, arbitrary following material will be accumulated into a `body' until the
               current grouping level is reverted, or till the "Token" is encountered if the
               option is a "Token".  This body is available as the "body" property of the
               Whatsit.  This is used by environments and math.

               Provides a control sequence to be used when reverting Whatsit's back to Tokens, in
               cases where it isn't the command used in the $prototype.

               This gives a number of args for cases where it can't be infered directly from the
               $prototype (eg. when more args are explictly read by Daemons).

               See "scope".

       "DefConstructorI($cs,$paramlist,$xmlpattern | $code,%options);"
           Internal form of "DefConstructor" where the control sequence and parameter list have
           already been parsed; useful for definitions from within code.

           A common shorthand constructor; it defines a control sequence that creates a
           mathematical object, such as a symbol, function or operator application.  The options
           given can effectively create semantic macros that contribute to the eventual parsing
           of mathematical content.  In particular, it generates an XMDual using the replacement
           $tex for the presentation.  The content information is drawn from the name and options

           These "DefConstructor" options also apply:

             reversion, alias, beforeDigest, afterDigest,
             beforeConstruct, afterConstruct and scope.

           Additionally, it accepts

               adds a style attribute to the object.

               gives a name attribute for the object

               gives the OpenMath content dictionary that name is from.

               adds a grammatical role attribute to the object; this specifies the grammatical
               role that the object plays in surrounding expressions.  This direly needs

               Specifies the font to be used for when creating this object.  See "MergeFont".

               Controls whether any sub and super-scripts will be stacked over or under this
               object, or whether they will appear in the usual position.

               WRONG: Redocument this!

               These two are similar to "role" and "scriptpos", but are used in unusual cases.
               These apply to the given attributes to the operator token in the content branch.

               Normally, these commands are digested with an implicit grouping around them, so
               that changes to fonts, etc, are local.  Providing "<noggroup="1>> inhibits this.

           Internal form of "DefMath" where the control sequence and parameter list have already
           been parsed; useful for definitions from within code.

           Defines an Environment that generates a specific XML fragment.  The $replacement is of
           the same form as that for DefConstructor, but will generally include reference to the
           "#body" property. Upon encountering a "\begin{env}":  the mode is switched, if needed,
           else a new group is opened; then the environment name is noted; the beforeDigest
           daemon is run.  Then the Whatsit representing the begin command (but ultimately the
           whole environment) is created and the afterDigestBegin daemon is run.  Next, the body
           will be digested and collected until the balancing "\end{env}".   Then, any
           afterDigest daemon is run, the environment is ended, finally the mode is ended or the
           group is closed.  The body and "\end{env}" whatsit are added to the "\begin{env}"'s
           whatsit as body and trailer, respectively.

           It shares options with "DefConstructor":

            mode, requireMath, forbidMath, properties, nargs,
            font, beforeDigest, afterDigest, beforeConstruct,
            afterConstruct and scope.

           Additionally, "afterDigestBegin" is effectively an "afterDigest" for the "\begin{env}"
           control sequence.

           Internal form of "DefEnvironment" where the control sequence and parameter list have
           already been parsed; useful for definitions from within code.

   Class and Packages
           Finds and loads a package implementation (usually "*.sty.ltxml", unless "raw" is
           specified) for the required $package.  The options are:

           "type=>type" specifies the file type (default "sty".
           "options=>[...]" specifies a list of package options.
           "raw=>1" specifies that it is allowable to try to read a raw TeX style file.
           Finds and loads a class definition (usually "*.cls.ltxml").  The only option is

           "options=>[...]" specifies a list of class options.
           Find an appropriate file with the given $name in the current directories in
           "SEARCHPATHS".  If a file ending with ".ltxml" is found, it will be preferred.  The
           options are:

           "type=>type" specifies the file type (default "sty".
           "raw=>1" specifies that it is allowable to try to read a raw TeX style file.
           Declares an option for the current package or class.  The $code can be a string or
           Tokens (which will be macro expanded), or can be a code reference which is treated as
           a primitive.

           If a package or class wants to accomodate options, it should start with one or more
           "DeclareOptions", followed by "ProcessOptions()".

           Causes the given @options (strings) to be passed to the package (if $ext is "sty") or
           class (if $ext is "cls") named by $name.

           Processes the options that have been passed to the current package or class in a
           fashion similar to LaTeX.  If the keyword "inorder=>1" is given, the options are
           processed in the order they were used, like "ProcessOptions*".

           Process the options given explicitly in @options.

   Counters and IDs
           Defines a new counter, like LaTeX's \newcounter, but extended.  It defines a counter
           that can be used to generate reference numbers, and defines \the$ctr, etc. It also
           defines an "uncounter" which can be used to generate ID's (xml:id) for unnumbered
           objects.  $ctr is the name of the counter.  If defined, $within is the name of another
           counter which, when incremented, will cause this counter to be reset.  The options are

              idprefix  Specifies a prefix to be used to generate ID's
                        when using this counter
              nested    Not sure that this is even sane.

       "$num = CounterValue($ctr);"
           Fetches the value associated with the counter $ctr.

       "$tokens = StepCounter($ctr);"
           Analog of "\stepcounter", steps the counter and returns the expansion of "\the$ctr".
           Usually you should use "RefStepCounter($ctr)" instead.

       "$keys = RefStepCounter($ctr);"
           Analog of "\refstepcounter", steps the counter and returns a hash containing the keys
           "refnum="$refnum, id=>$id>.  This makes it suitable for use in a "properties" option
           to constructors.  The "id" is generated in parallel with the reference number to
           assist debugging.

       "$keys = RefStepID($ctr);"
           Like to "RefStepCounter", but only steps the "uncounter", and returns only the id;
           This is useful for unnumbered cases of objects that normally get both a refnum and id.

           Resets the counter $ctr to zero.

           Generates an ID for nodes during the construction phase, useful for cases where the
           counter based scheme is inappropriate.  The calling pattern makes it appropriate for
           use in Tag, as in
              Tag('ltx:para',sub { GenerateID(@_,'p'); })

           If $node doesn't already have an xml:id set, it computes an appropriate id by
           concatenating the xml:id of the closest ancestor with an id (if any), the prefix and a
           unique counter.

   Document Model
       Constructors define how TeX markup will generate XML fragments, but the Document Model is
       used to control exactly how those fragments are assembled.

           Declares properties of elements with the name $tag.

           The recognized properties are:

               Specifies whether this $tag can be automatically opened if needed to insert an
               element that can only be contained by $tag.  This property can help match the more
               SGML-like LaTeX to XML.

               Specifies whether this $tag can be automatically closed if needed to close an
               ancestor node, or insert an element into an ancestor.  This property can help
               match the more  SGML-like LaTeX to XML.

               Provides CODE to be run whenever a node with this $tag is opened.  It is called
               with the document being constructed, and the initiating digested object as
               arguments.  It is called after the node has been created, and after any initial
               attributes due to the constructor (passed to openElement) are added.

               Provides CODE to be run whenever a node with this $tag is closed.  It is called
               with the document being constructed, and the initiating digested object as

           Specifies the schema to use for determining document model.  You can leave off the
           extension; it will look for ".rng", and maybe eventually, ".rnc" once that is

           Declares the $prefix to be associated with the given $URL.  These prefixes may be used
           in ltxml files, particularly for constructors, xpath expressions, etc.  They are not
           necessarily the same as the prefixes that will be used in the generated document (See

           Declares the expected rootelement, the public and system ID's of the document type to
           be used in the final document.  The hash %namespaces specifies the namespaces prefixes
           that are expected to be found in the DTD, along with each associated namespace URI.
           Use the prefix "#default" for the default namespace (ie. the namespace of non-prefixed
           elements in the DTD).

           The prefixes defined for the DTD may be different from the prefixes used in
           implementation CODE (eg. in ltxml files; see RegisterNamespace).  The generated
           document will use the namespaces and prefixes defined for the DTD.

   Document Rewriting
       During document construction, as each node gets closed, the text content gets simplfied.
       We'll call it applying ligatures, for lack of a better name.

           Apply the regular expression (given as a string: "/fa/fa/" since it will be converted
           internally to a true regexp), to the text content.  The only option is
           "fontTest=CODE($font)"; if given, then the substitution is applied only when
           "fontTest" returns true.

           Predefined Ligatures combine sequences of "." or single-quotes into appropriate
           Unicode characters.

           CODE is called on each sequence of math nodes at a given level.  If they should be
           replaced, return a list of "($n,$string,%attributes)" to replace the text content of
           the first node with $string content and add the given attributes.  The next "$n-1"
           nodes are removed.  If no replacement is called for, CODE should return undef.

           Predefined Math Ligatures combine letter or digit Math Tokens (XMTok) into
           multicharacter symbols or numbers, depending on the font (non math italic).

       After document construction, various rewriting and augmenting of the document can take

           These two declarations define document rewrite rules that are applied to the document
           tree after it has been constructed, but before math parsing, or any other
           postprocessing, is done.  The %specification consists of a seqeuence of key/value
           pairs with the initial specs successively narrowing the selection of document nodes,
           and the remaining specs indicating how to modify or replace the selected nodes.

           The following select portions of the document:

           label =>$label
               Selects the part of the document with label=$label

           scope =>$scope
               The $scope could be "label:foo" or "section:1.2.3" or something similar. These
               select a subtree labelled 'foo', or a section with reference number "1.2.3"

           xpath =>$xpath
               Select those nodes matching an explicit xpath expression.

           match =>$TeX
               Selects nodes that look like what the processing of $TeX would produce.

               Selects text nodes that match the regular expression.

           The following act upon the selected node:

           attributes => $hash
               Adds the attributes given in the hash reference to the node.

           replace =>$replacement
               Interprets the $replacement as TeX code to generate nodes that will replace the
               selected nodes.

   Mid-Level support
       "$tokens = Expand($tokens);"
           Expands the given $tokens according to current definitions.

       "$boxes = Digest($tokens);"
           Processes and digestes the $tokens.  Any arguments needed by control sequences in
           $tokens must be contained within the $tokens itself.

       "@tokens = Invocation($cs,@args);"
           Constructs a sequence of tokens that would invoke the token $cs on the arguments.

       "RawTeX('... tex code ...');"
           RawTeX is a convenience function for including chunks of raw TeX (or LaTeX) code in a
           Package implementation.  It is useful for copying portions of the normal
           implementation that can be handled simply using macros and primitives.

           Gives $token1 the same `meaning' (definition) as $token2; like TeX's \let.

   Argument Readers
           Reads from $gullet the tokens corresponding to $spec (a Parameters object).

           Defines a new Parameter type, $type, with CODE for its reader.

           Options are:

               This CODE is responsible for converting a previously parsed argument back into a
               sequence of Token's.

               whether it is an error if no matching input is found.

               whether the value returned should contribute to argument lists, or simply be
               passed over.

               whether the catcode table should be modified before reading tokens.

           Defines a new column type for tabular and arrays.  $proto is the prototype for the
           pattern, analogous to the pattern used for other definitions, except that macro being
           defined is a single character.  The $expansion is a string specifying what it should
           expand into, typically more verbose column specification.

   Access to State
       "$value = LookupValue($name);"
           Lookup the current value associated with the the string $name.

           Assign $value to be associated with the the string $name, according to the given
           scoping rule.

           Values are also used to specify most configuration parameters (which can therefor also
           be scoped).  The recognized configuration parameters are:

            VERBOSITY         : the level of verbosity for debugging
                                output, with 0 being default.
            STRICT            : whether errors (eg. undefined macros)
                                are fatal.
            INCLUDE_COMMENTS  : whether to preserve comments in the
                                source, and to add occasional line
                                number comments. (Default true).
            PRESERVE_NEWLINES : whether newlines in the source should
                                be preserved (not 100% TeX-like).
                                By default this is true.
            SEARCHPATHS       : a list of directories to search for
                                sources, implementations, etc.

           This is like "AssignValue", but pushes values onto the end of the value, which should
           be a LIST reference.  Scoping is not handled here (yet?), it simply pushes the value
           onto the last binding of $name.

           Similar to  "PushValue", but pushes a value onto the front of the values, which should
           be a LIST reference.

       "$value = LookupCatcode($char);"
           Lookup the current catcode associated with the the character $char.

           Set $char to have the given $catcode, with the assignment made according to the given
           scoping rule.

           This method is also used to specify whether a given character is active in math mode,
           by using "math:$char" for the character, and using a value of 1 to specify that it is

       "$meaning = LookupMeaning($token);"
           Looks up the current meaning of the given $token which may be a Definition, another
           token, or the token itself if it has not otherwise been defined.

       "$defn = LookupDefinition($token);"
           Looks up the current definition, if any, of the $token.

           Install the Definition $defn into $STATE under its control sequence.

   Low-level Functions
           Cleans a $label of disallowed characters, prepending $prefix (or "LABEL", if none

           Cleans an index key, so it can be used as an ID.

           Cleans a bibliographic citation key, so it can be used as an ID.

           Cleans a url.

           Generates a UTF character, handy for the the 8 bit characters.  For example,
           "UTF(0xA0)" generates the non-breaking space.

           Set the current font by merging the font style attributes with the current font.  The
           attributes and likely values (the values aren't required to be in this set):

            family : serif, sansserif, typewriter, caligraphic,
                     fraktur, script
            series : medium, bold
            shape  : upright, italic, slanted, smallcaps
            size   : tiny, footnote, small, normal, large,
                     Large, LARGE, huge, Huge
            color  : any named color, default is black

           Some families will only be used in math.  This function returns nothing so it can be
           easily used in beforeDigest, afterDigest.

       "@tokens = roman($number);"
           Formats the $number in (lowercase) roman numerals, returning a list of the tokens.

       "@tokens = Roman($number);"
           Formats the $number in (uppercase) roman numerals, returning a list of the tokens.


       Bruce Miller <>


       Public domain software, produced as part of work done by the United States Government &
       not subject to copyright in the US.