Copyright Bruce Wilcox, gowilcox@gmail.com www.brilligunderstanding.com
Revision 5/30/2020 cs10.4

• Engine-defined Concepts
• System Variables
• Control over Input
• Interchange Variables

Engine-defined concepts

In addition to concepts defined in script files, the system automatically defines a bunch of dictionary-based sets as well as dynamically computed concept members.

set	description
~web_url	word is a web url
~email_url	word is an email address
~kindergarten	word learned early in life
~grade1_2	word learned in these grades
~grade3_4	word learned in these grades
~grade_5-6	word learned in these grades. Unmarked words are learned even later
~utf8	word has nonascii characters
~daynumber	word could be a number of a day in a month
~yearnumber	word could be the number of a recent year
~dateinfo	phrase is month day year of some kind
~kelvin	temperature marker
~celcius	temperature marker
~fahrenheit	temperature marker
~twitter_name	twitter user name
~hashtag_label	twitter topic reference

Interjections, "discourse acts", and concept sets

Some words and phrases have interpretations based on whether they are at sentence start or not. E.g., good day, mate and It is a good day are different for good day.

Likewise sure and I am sure are different.

Words that have a different meaning at the start of a sentence are commonly called interjections.

In ChatScript these are defined by the livedata/interjections.txt file. In addition, the file augments this concept with "discourse acts", phrases that are like an interjection. All interjections and discourse acts map to concept sets, which come thru as the user input instead of what they wrote.

For example yes and sure and of course are all treated as meaning the discourse act of agreement in the interjections file. So you don’t see yes, I will go coming out of the engine.

The interjections file will remap that to the sentence ~yes, breaking off that into its own sentence, followed by I will go as a new sentence.

These generic interjections (which are open to author control via interjections.txt) are:

interjection	description
~yes
~no
~emomaybe
~emohello
~emogoodbye
~emohowzit
~emothanks
~emolaugh
~emohappy
~emosad
~emosurprise
~emomisunderstand
~emoskeptic
~emoignorance
~emobeg
~emobored
~emopain
~emoangry
~emocurse
~emodisgust
~emoprotest
~emoapology
~emomutual

Because all interjections at the start of a sentence are broken off into their own sentence, this kind of pattern does not work:

u: (~yes _*)

You cannot capture the rest of the sentence here, because it will be part of the next sentence instead. This means interjections act somewhat differently from other concepts.

If you use a word in a pattern which may get remapped on input, the script compiler will issue a warning. Likely you should use the remapped name instead.

The following concepts are triggered by exactly repeating either the chatbot or oneself (to a repeat count of how often repeated). Repeats are within a recency window of about 20 volleys.

concept	description
~repeatme
~repeatinput1
~repeatinput2
~repeatinput3
~repeatinput4
~repeatinput5
~repeatinput6

POS (Part of Speech) Tags

Words will have pos-tags attached, specififying both generic and specific tag attributes, eg., ~noun, ~noun_singular.

Generic Specifics

nouns	description
~noun
~noun_singular
~noun_plural
~noun_proper_singular
~noun_proper_plural
~noun_gerund
~noun_number
~noun_infinitive
~noun_omitted_adjective

verbs	description
~verb
~verb_present
~verb_present_3ps
~verb_infinitive
~verb_present_participle
~verb_past
~verb_past_participle
~aux_verb
~aux_verb_present
~aux_verb_past
~aux_verb_future
~aux_verb_tenses
~aux_be
~aux_have
~aux_do

Auxilliary verbs are segmented into normal ones and special ones. Normal ones give their tense directly. Special ones give their root word. The tense of the be/have/do verbs can be had via ^properties() and testing for verb tenses

adjectives	description
~adjective
~adjective_normal
~adjective_number
~adjective_noun
~adjective_participle

adjectives in comparative form	description
~more_form ~most_form
~adverb
~adverb_normal

adverbs in comparative form	description
~more_form ~most_form
~pronoun ~pronoun_subject ~pronoun_object
~conjunction_bits ~conjunction_coordinate ~conjunction_subordinate
~determiner_bits ~determiner ~pronoun_possessive ~predeterminer
~possessive	covers ' and 's at end of word
~to_infinitive	"to" when used before a noun infinitive
~preposition ~particle	free-floating preposition tied to idiomatic verb
~comma
~quote	covers ' and " when not embedded in a word
~paren	covers opening and closing parens
~foreign_word	some unknown word
~there_existential	the word there used existentially

In addition to normal generic kinds of pos tags, words which are serving a pos-tag role different from their putative word type are marked as members of the major tag they act as part of. E.g,

	description
~noun_gerund	verb used as a ~noun
~noun_infinitive	verb used as a ~noun
~noun_omitted_adjective	an adjective used as a collective noun (eg the beautiful are kind)
~adjectival_noun	noun used as adjective like bank "bank teller"
~adjective_participle	verb participle used as an adjective

For ~noun_gerund in I like swimming the verb gerund swimming is treated as a noun (hence called noun-gerund) but retains verb sense when matching keywords tagged with part-of-speech (i.e., it would match swim~v as well as swim~n).

Additionally, there is

	description
~number	is not a part of speech, but is comprise of ~noun_number (a normal number value like 17 or seventeen)
~adjective_number	also a normal numeral value and also ~placenumber) like first.
~integer
~float
~positiveinteger
~negativeinteger
~modelnumber	not a true number, but a word with both alpha and numeric
~filename	looks like a filename with extension

To can be a preposition or it can be special. When used in the infinitive phrase To go, it is marked ~to_infinitive and is followed by ~noun_infinitive.

	description
~verb_infinitive	refers to a match on the infinitive form of the verb (I hear John sing or I will sing).
~There_existential	refers to the use of where not involving location, meaning the existence of, as in There is no future.
~Particle	refers to a preposition piece of a compound verb idiom which allows being separated from the verb. If you say I will call off the meeting, call_off is the composite verb and is a single token. But if you split it as in I will call the meeting off, then there are two tokens. The original form of the verb will be call and the canonical form of the verb will be call_off, while the free-standing off will be labeled ~particle.
~verb_present	will be used for normal present verbs not in third person singular like I walk and
~verb_present_3ps	will be used for things like he walks
~possesive	refers to ‘s and ‘ that indicate possession, while possessive pronouns get their own labeling ~pronoun_possessive.
~pronoun_subject	is a pronoun used as a subject (like he)
~pronoun_object	refers to objective form like him

Individual words serve roles in the parse of a sentence, which are retrievable. These include:

	description
~mainsubject
~mainverb
~mainindirect
~maindirect
~subject2
~verb2
~indirectobject2
~object2
~subject_complement	adjective object of sentence involving linking verb
~object_complement	2ndary noun or infinitive verb filling modifying mainobject or object2
~conjunct_noun ~conjunct_verb ~conjunct_adjective ~conjunct_adverb ~conjunct_phrase ~conjunct_clause ~conjunct_sentence
~postnominalAdjective	adjective occuring AFTER the noun it modified
~reflexive	reflexive pronouns
~not
~address	noun used as addressee of sentence
~appositive	noun restating and modifying prior noun
~absolutephrase	special phrase describing whole sentence
~omittedtimeprep	modified time word used as phrase but lacking preposition (Next tuesday I will go)
~phrase	a prepositional phrase start (except
~clause	a subordinate clause start
~verbal	a verb phrase

and special concepts: | ~capacronym | word is in all caps (and &) and is likely an acronym | ~emoji | word starts and end with : and represents an emoji

System Variables

The system has some predefined variables which you can generally test and use but not normally assign to. These all begin with % . Ones that are reasonable to set are written in bold underline. Boolean values are always 1 or null on returns. 1 or 0 if you are setting them.

Date & Time & Numbers

variable	description
%date	one or two digit day of the month
%day	Sunday, etc
%daynumber	1-7 where 1 = Sunday
%fulltime	seconds representing the current time and date (Unix epoch time)
%hour	0-23
%timenumbers	completely consistent full time info in numbers that you can do _0 = ^burst(%timenumbers)to get _0 =seconds (2digit) _1=minutes (2digit) _2=hours (2digit) _3=dayinweek(0-6 Sunday=0) _4=dateinmonth (1-31) _5=month(0-11 January=0) _6=year. You need to get it simultaneously if you want to do accurate things with current time, since retrieving %hour %minute separately allows time to change between calls
%leapyear	boolean if current year is a leap year
%daylightsavings	boolean if current within daylight savings
%minute	0-59
%month	1-12 (January = 1)
%monthname	January, etc
%second	0-59
%volleytime	number of seconds of computation since volley input started
%time	hh:mm in military 24-hour time
%zulutime	2016-07-27T11:38:35.253Z
%week	1-5 (week of the month)
%year	e.g., 2011
%rand	get a random number from 1 to 100 inclusive

Time and date information are normally local, relative to the system clock of the machine CS is running on. See $cs_utcoffset for adjusting time based on relationship to utc (e.g your server is in Virginia and you are in Colorado).

User Input

variable	description
%bot	current bot responding
%revisedinput	Boolean is current input from ^input not direct from user
%command	Boolean was the user input a command
%foreign	Boolean is bulk of the sentence composed of foreign words
%impliedyou	Boolean was the user input having you as implied subject
%input	the count of the number of volleys this user has made ever
%ip	ip address supplied
%language	current dictionary language
%length	the length in tokens of the current sentence
%more	Boolean is there another sentence after this
%morequestion	Boolean is there a ? or question word in the pending sentences
%originalinput	all sentences user passed into volley, before adjusted in any way except OOB data is stripped off
%originalsentence	the current sentence after tokenization but before any adjustments
%parsed	Boolean was current input parsed successfully
%question	Boolean was the user input a question - same as ? in a pattern
%quotation	Boolean is current input a quotation
%sentence	Boolean does it seem like a sentence (subject/verb or command)
%tableinput	current line being executed in a table expansion during script compilation
%tense	past , present, or future simple tense (present perfect is a past tense)
%user	user login name supplied
%userfirstline	value of %input that is at the start of this conversation start
%userinput	Boolean is the current input from the user (vs the chatbot)
%voice	active or passive on current input

Chatbot Output

variable	description
%inputrejoinder	rule tag of any pending rejoinder for input or null if none pending
%lastoutput	the text of the last generated response for the current volley - always null across volleys
%lastquestion	Boolean did last output end in a ?
%outputrejoinder	rule tag if system set a rejoinder for its current output or 0
%response	number of committed responses that have been generated for this sentence (see Advanced User- Advanced Output: Committed Responses

System variables

variable	description
%all	Boolean is the :all flag on? (:all to set)
%document	Boolean is :document running
%fact	Numeric value most recent fact id
%freetext	kb of available text space
%freedict	number of unused dictionary words
%freefact	number of unused facts
%maxmatchvariables	highest number of match variables, currently 20
%maxfactsets	highest number of @factsets, currently 20
%host	name of the current host machine or "local"
%regression	Boolean is the regression flag on
%server	Boolean is the system running in server mode
%rule	get a tag to the current executing rule. Can be used in place of a label
%topic	name of the current "real" topic . if control is currently in a topic or called from a topic which is not system or nostay, then that is the topic. Otherwise the most recent pending topic is found
%actualtopic	literally the current topic being processed (system or not)
%trace	Numeric value of the trace flag (:trace to set)
%httpresponse	return code of most recent ^jsonopen call
%pid	Linux process id or 0 for other systems
%restart	You can set and retrieve a value here across a system restart.
%timeout	Boolean tells if a timeout has happened, based on the timelimit command line parameter
%lastcurltime	Time Analysis: Name Look up: Host/proxy connect: App(SSL) connect: Pretransfer: Total Transfer:
%crosstalk	4k buffer in server visible between users to pass data back and forth
%crosstalk1	4k buffer in server visible between users to pass data back and forth

Build data

variable	description
%dict	date/time the dictionary was built
%engine	date/time the engine was compiled
%os	os invovled (linux windows mac ios)
%script	date/time build1 was compiled
%version	engine version number

You actually can assign to any of them. This will override them and make them return what you tell them to and is a particularly BAD thing to do if this is running on a server since it affects all users (unless you reset the variable at the end of the volley. Assigning a period to a variable resets it).

Typically one does this as a temporary assignment in a #! comment line to set up conditions for testing using :verify.

Making them return a new value is NOT the same thing as making the engine have a different value. Unless the variable is marked as settable, setting a value affects only the value returned by a future call to the system variable. It does not change engine values the variable is meant to reflect.

Control Over Input

The system can do a number of standard processing on user input, including spell correction, proper-name merging, expanding contractions etc. This is managed by setting the user variable $cs_token.

The default one that comes with Harry is:

$cs_token = #DO_INTERJECTION_SPLITTING | 
            #DO_SUBSTITUTE_SYSTEM |
            #DO_NUMBER_MERGE | 
            #DO_PROPERNAME_MERGE | 
            #DO_SPELLCHECK |
            #DO_PARSE

The #signals a named constant from the dictionarySystem.h file. One can set the following:

These enable various LIVEDATA files to perform substitutions on input:

flag	description
#DO_ESSENTIALS	perform LIVEDATA/systemessentials which mostly strips off trailing punctuation and sets corresponding flags instead
#DO_SUBSTITUTES	perform LIVEDATA/substitutes
#DO_CONTRACTIONS	perform LIVEDATA/contractions, expanding contractions
#DO_INTERJECTIONS	perform LIVEDATA/interjections, changing phrases to interjections
#DO_BRITISH	perform LIVEDATA/british, respelling brit words to American
#DO_SPELLING	performs the LIVEDATA/spelling file (manual spell correction)
#DO_TEXTING	performs the LIVEDATA/texting file (expand texting notation)
#DO_SUBSTITUTE_SYSTEM	do all LIVEDATA file expansions
#DO_INTERJECTION_SPLITTING	break off leading interjections into own sentence
#$DO_NUMBER_MERGE	merge multiple word numbers into one (four and twenty)
#$DO_PROPERNAME_MERGE	merge multiple proper name into one (George Harrison)
#DO_DATE_MERGE	merge month day and/or year sequences (January 2, 1993)
#JSON_DIRECT_FROM_OOB	asking the tokenizer to directly process OOB data. See ^jsonparse in JSON manual.

The contents of the files are pairs of tokens per line. Left is the word to replace and right is the replacement. When multiple words are involved, the left side uses underscores to represent this and the right side uses +. If the right side is missing, it means just delete.

If any of the above items affect the input, they will be echoed as values into %tokenFlags so you can detect they happened. The next changes do not echo into %tokenFlags and relate to grammar of input:

flag	description
DO_POSTAG	allow pos-tagging (labels like ~noun ~verb become marked)
DO_PARSE	allow parser (labels for word roles like ~main_subject)
DO_CONDITIONAL_POSTAG	perform pos-tagging only if all words are known. Avoids wasting time on foreign sentences in particular
NO_CONDITIONAL_IDIOM	will not perform substitutions in the dictionary which are considered conditional idioms
NO_ERASE	where a substitution would delete a word entirely as junk, don't
DO_SPLIT_UNDERSCORES	happens after all other input tokenization and adjustments except number merge, and separates words that have been conjoined either because the dictionary has them (credit_card) or because they were merged by proper name merging, or by substitution. The result is only words without underscores (excluding number words like five_thousand_and_four
MARK_LOWER	if a word is considered a proper name in CS and is marked as an upper case word, this will force it to perform any markings for its lower case form as well. Sometimes users type stuff in upper case that really should be lower

Normally the system tries to outguess the user, who cannot be trusted to use correct punctuation or casing or spelling. These block that:

flag	description
STRICT_CASING	except for 1st word of a sentence, assume user uses correct casing on words
NO_INFER_QUESTION	the system will not try to set the QUESTIONMARK flag if the user didn't input a ? and the structure of the input looks like a question
DO_SPELLCHECK	perform internal spell checking
ONLY_LOWERCASE	force all input (except "I") to be lower case, refuse to recognize uppercase forms of anything
NO_IMPERATIVE
NO_WITHIN	don't match fragments within a composite word
NO_SENTENCE_END	do not break input into sentences

Normally the tokenizer breaks apart some kinds of sentences into two. These prevent that:

flag	description
NO_COLON_END	don't break apart a sentence after a colon
NO_SEMICOLON_END	don't break apart a sentence after a semi-colon
UNTOUCHED_INPUT	if set to this alone, will tokenize only on spaces, leaving everything but spacing untouched
LEAVE_QUOTE	if input is found within " " it will become a single token exactly as it is seen. W/o Leave_Quote, it is converted into a word without quotes and using underscores instead of spaces. So "My Fair Lady" becomes My_Fair_Lady, which would match a movie title if you had one, unlike My Fair Lady becoming the resulting token and unrecognized
SPLIT_QUOTE	if input is found within " " the quotes will be removed.

Note

you can change $cs_token on the fly and force input to be reanalyzed via ^retry(SENTENCE). I do this when I detect the user is trying to give his name, and many foreign names might be spell-corrected into something wrong and the user is unlikely to misspell his own name.

Just remember to reset $cs_token back to normal after you are done. Here is one such way, assuming $stdtoken is set to your normal tokenflags in your bot definition outputmacro:

#! my name is Rogr
s: (name is _*)

    if ($cs_token == $stdtoken)
        {
        $cs_token = #DO_INTERJECTION_SPLITTING |
                    #DO_SUBSTITUTE_SYSTEM | #DO_NUMBER_MERGE |
                    #DO_PARSE
        retry(SENTENCE)
        }
    _0 is the name.
    $cs_token = $stdtoken

If you type my name is Rogr into a topic with this, the original input is spell-corrected to my name is Roger, but this will change the $cs_token over to one without spell correction and redo the sentence, which will now come back with my name is Rogr and be echoed correctly, and $cs_token reset.

That's assuming nothing else would run differently and trap the response elsewhere. If you were worried about that, it would be possible for the script to save where it is using ^getrule(tag) and modify your control script to return immediate control to here after input processing if you had changed $cs_token.

Private Substitutions

While in general, substitutions are defined in the LIVEDATA folder, you can define private substititions for your specific bot using the scripting language. You can say

replace: xxx yyyyy

which defines a substitution just like a livedata substitution file. It actually creates a substitution file called private0.txt or private1.txt in your TOPIC folder.

Even then, those substitutions will not be enacted unless you explicitly add to the $cs_token value #DO_PRIVATE, eg

$cs_token = #DO_INTERJECTION_SPLITTING | 
            #DO_SUBSTITUTE_SYSTEM |
            #DO_NUMBER_MERGE | 
            #DO_PROPERNAME_MERGE |
            #DO_SPELLCHECK | 
            #DO_PARSE | 
            #DO_PRIVATE

The left side of the substitution pair is case insensitive (matches either case on input) and can be placed in double-quotes (which converts spaces to underscores internally).

The right side of the substitution pair is case sensitive and can be placed in double-quotes (which converts spaces to plus signs internally).

Similarly while canonical values of words can be defined in LIVEDATA/SYSTEM/canonical.txt, you can define private canonical values for your bots by using the scripting language. You can say:

canon: oh 0 
canon: faster fast

which defines new canonical values for things and creates a file canon0.txt or canon1.txt in your TOPIC folder.

You can optionally add MORE_FORM or MOST_FORM as a 3rd argument, to set those flags for adjectives and adverbs.

If you want to set a canonical pair from a table during compilation, you can use a function to do the same thing (but only 1 pair at a time).

^canon(word canonicalform)

Numeric Substitutions

A special kind of private substitution (equally applicable in regular substitution files) is the numeric substitution.

replace: ?_km kilometers

The ?_ matches a digit number followed immediately by km, like 1.2km and will separate the number and replace the units with the given replacement. The input can be singular or have an 's' like 10.5dollars. And it can be with or without abbreviation periods, like 10kps or 10k.p.s

Apostrophe Substitutions replace

replace: 'xxx  yyy

allows you to split during tokenization any word followed by 'xxx into two words, original sans 'xxx and yyy. eg

replace: 've have

gives "companies've => "companies have".

Replacing to a word with + in it

Normally replace: x y+z will generate 2 words, y and z. If you need a plus in your word, you can escape your 2nd word:

    replace: "black and decker" \BLACK+DECKER

Interchange Variables

The following variables can be defined in a script and the engine will react to their contents.

interchange variable	description
$cs_token	described extensively above
$cs_response	controls automatic handling of outputs to user. By default it consists of `$cs_response = #Response_upperstart
$cs_jsontimeout	seconds before JsonOpen declares a time out failure. If unspecified the default is 300
$cs_crashmsg	in server mode, what to say if the server crashes and we return a message to the user. By default the message is Hey, sorry. I forgot what I was thinking about.
$cs_abstract	used with :abstract
$cs_looplimit	loop() defaults to 1000 iterations before stopping. You can change this default with this
$cs_trace	if this variable is defined, then whenever the user's volley is finished, the value of this variable is set to that of :trace and :trace is cleared to 0, but when the user is read back in, the :trace is set to this value. For a server, this means you can perform tracing on a user w/o making all user transactions dump trace data
$cs_control_pre	name of topic (flag it SYSTEM) to run in gambit mode on pre-pass, set by author. Runs before any sentences of the input volley are analyzed. Good for setting up initial values
$cs_usermessagelimit	max number of message pairs (user input & bot output) saved in topic file
$cs_externaltag	name of a topic to use to replace existing internal English pos-parser. See bottom of ChatScript PosParser manual for details
$cs_prepass	name of a topic (mark it SYSTEM) to run in responder mode on main volleys, which runs before $cs_control_main and after all of the above and pos-parsing is done. Used to amend preparation data coming from the engine. You can use it to add your own spin on input processing before going to your main control. I use it to, for example, label commands as questions, standardize sentence construction (like if you see me what will you think to assume you see me. What will you think?)
$cs_control_main	name of topic (flag it SYSTEM) to run in responder mode on main volleys, set by author
$cs_control_post	name of topic (flag it SYSTEM) to run in gambit mode on post-pass, set by author
$botprompt	message for console window to label bot output
$userprompt	message for console window to label user input line
$cs_crashmsg	message to use if a server crash occurs
$cs_language	if spanish, will adjust spell checking for spanish colloquial
$cs_token	bits controlling how the tokenizer works. By default when null, you get all bits assumed on. The possible values are in src/dictionarySystem.h (hunt for $token) and you put a # in front of them to generate that named numeric constant
$cs_abstract	topic used by :abstract to display facts if you want them displayed
$cs_prepass	topic used between parsing and running user control script. Useful to supplement parsing, setting the question value, and revising input idioms
$cs_wildcardseparator	when a match variable covers multiple words, what should separate them- by default it's a space, but underscore is handy too. Initial system character is space, creating fidelity with what was typed. Useful if _ can be recognized in input (web addresses). Changing to _ is consistent with multi-word representation and keyword recognition for concepts. CS automatically converts _ to space on output, so internal use of _ is normal
$cs_userfactlimit	how many of the most recent permanent facts created by the script in response to user inputs are kept for each user. Std default is 100. * means all.
$cs_outputchoice	for regression: forces specific one of a [] [] output choice block - base 0
$cs_response	controls some characteristics of how responses are formatted
$cs_randIndex	the random seed for this volley
$cs_utcoffset	if defined, then %time returns current utc time + timezone offset. The offset is usually a simple number, meaning hours, and can have + or - in front of it. It can also be a normal time reference like 02:30 which means plus 2 hours and 30 minutes beyond utc, or -01:30:20 which means 1 hour, 30 minutes, and 20 seconds before utc (as if anyone would use that). The following variables are generated by the system on behalf of scripts
$$db_error	error message from a postgres failure $$findtext_start - ^findtext return the end normally, this is where it puts the start
$$tcpopen_error	error message from a tcpopen error
$$document	name of the document being read in document mode
$cs_randindex	current value of the random generator value
$cs_bot	name of the bot currently in use
$cs_login	login name of the user
$$csmatch_start	start of found words from ^match
$$csmatch_end	end of found words from ^match
$cs_fullfloat	if defined, causes the system to generate full float 64-bit precision on outputs, otherwise you get 2 digit precision by default
$cs_botid	when non-zero creates facts and functions restricted by this bitmask so facts and functions created by other masks cannot be seen. allows you to separate facts and functions per bot in a multi-bot environment. During compilation if this is set by a bot: command, then functions created and facts created by tables will be restricted to that owner.
$cs_numbers	if defined, causes the system to output numbers in a different language style: french, indian. All other values are english.
$cs_topicretrylimit	if defined changes how many times you can pass back RETRY_TOPIC before it fails (current limit is 30)
$$topic_retry_limit_exceeded	set if topic retry limit is encountered
$cs_topicretrylimit	if defined changes how many times you can pass back RETRY_TOPIC before it fails (current limit is 30)
$cs_userhistorylimit	if not null, indicates how many volleys back are tracked as what was said by both parties
$cs_saveusedJson	if not null, the only JSON facts CS will write into the user's topic files that are referred to (directly or indirectly) from user variables being saved. (see below)
$cs_proxycredentials	See ^JSONOPEN in JSON manual
$cs_proxyserver	See ^JSONOPEN in JSON manual
$cs_proxymethod	See ^JSONOPEN in JSON manual
$cs_addresponse	provides a function name hook onto the output q to the user. See below.
$cs_tracepattern	Used by the ^testpattern call to let pattern code request a trace of pattern matching be returned.
$cs_indentlevel	controls indenting when tracing in ^testpattern. 3 is a good number usually
`$cs_tracetestoutput	set to 1 to force tracing in ^testoutput
`$cs_sentences_limit	after this many sentences in volley, cs ignores the rest (default 50)
`$cs_outputlimit	Generating more output than this will report a bug into LOGS/bugs.txt
$cs_summary	After volley prints to terminal milliseconds of time used in preparation, rules, postprocessing
$cs_showtime	After volley prints to terminal milliseconds of time used

$cs_saveusedJson exists as a kind of garbage collection. Nowadays most facts will come from JSON data either from a website or created in script. But keeping on top of deleting obsolete JSON may be overlooked. When this variable is non-null, ChatScript will automatically destroy any JSON fact that cannot trace a JSON fact path back to some user variable. Variables that have as values the name of a JSON object or array automatically protect all JSON facts underneath. JSON references merely within some text string will not protect anything, nor will references from some other non-JSON fact.

$cs_addresponse names a function of 2 arguments that will be called when CS wants put text into the output queue of the user. The first argument will be what CS wants to output. The second is the rule tag that generated this output. If the function returns a failure code, the message will be aborted and not put into the queue. If the function returns a text value (not null) then that message will replace what was intended to go to the user.