1. Cognitive architecture Diagram of EnThink English-thinking Mind-Module

  /^^^^^^^^^^^\EnThink is for Thinking in English /^^^^^^^^^^^\
 /   EYE       \            _________________    /    EAR      \
|               |CONCEPTS  /                 \  |  ___________  |
|   _______     |   | | | / Volition FreeWill \ | / MindBoot  \ |
|  / old   \    |   | | | \___________________/ || memory vault||
| / image   \!!!|!!!|!|!| __|____  |   _|____   ||             ||
| \ recog   /---|---|-|-+(Emotion) |  /      \  || "students"  ||
|  \_______/    |   |s| | \_____/  | (RuThink ) || "read"      ||
|               |   |t| |   _______V  \______/  || "books"     ||
|               |   |u| |  /        \           | \___________/ |
|               |   |d|b| ( EnThink  )          |               |
|   visual      |  r|e|o|  \________/\_______   | "John is a"   |
|               |  e|n|o|   |     |  /       \  | "student"     |
|   memory      |  a|t|k|   |     | (InFerence) |               |
|               |  d|s|s|   |     |  \_______/  | "John reads"  |
|   channel     |   | | |   |    _V__________   | "books"       |
|               |   | | |   |   / Imperative \  |               |
|               |   | | |   |   \____________/  |               |
|   _______     |   | | |  _V__________         |               |
|  /new    \    |   |_|_| ( Indicative )        |newest memories|
| / percept \   |  /     \ \__________/         |to be recycled |
| \ engram  /---|-(  Psy  )                     |automatically  |
|  \_______/    |  \_____/                      |by ReJuvenate()|

2. Purpose of the AI4U Textbook EnThink English Thinking Module

The EnThink English-thinking module, like the RuThink Russian-thinking module and the LaThink Latin-thinking module, carries out the wish of the Volition module to engage in thinking with natural language. EnThink is at the center of the AI 102 curriculum for a one-year course in artificial intelligence for community colleges and vocational technical schools leading to a Certificte for AI Mind Maintainer. An AI Mind taking advantage of Unicode mutatis mutandis may be built to think in any human language.

3. Algorithm of the AI4U Textbook EnThink English Thinking AI Mind-Module

EnThink calls the various subordinate thinking modules such as Imperative or Indicative or InFerence.

4. Code of EnThink() from ghost327.pl AI source code in Perl

sub EnThink() {      # http://ai.neocities.org/EnThink.html
  $catsubj = 0;  # 2019-01-28: reset for safety;
  $catverb = 0;  # 2019-01-28: reset for safety.
  $tpr = 0;  # 2019-08-06: reset after service as flag-panel tag for concepts.
  if ($isolation > 256) {  # 2018-10-08: if AI not given input for too long...
    Imperative();  # 2018-09-19: Issue a request for input from a human user.
    $isolation=0;  # 2018-10-08: reset the trigger for calling Imperative().
    return;    # 2018-11-01: abandon EnThink(); give human user a chance to respond. 
  }  # 2018-11-01: end of test for trigger to call Imperative()
  if ($qucon==1 || $whatcon==1 || $wherecon==1) { SpreadAct() }  # 2018-11-01
# $wherecon = 0;     # 2018-11-04: reset for safety. 
  if ($nucon > 0) {  # 2017-11-29: if a new noun is encounter in NewConcept()
    SpreadAct();     # 2017-11-29: to activate concepts for a question. 
    $nucon = 0;      # 2017-11-29: reset for safety.
    $pov = 2;        # 2017-11-29: give human user a "pause" for input...
    $gapcon = 21;     # 2017-11-29: arbitrary pause for human input...
    return;    # 2017-11-29: after question abandon rest of function.
  }  # 2017-09-29: end of test.
  if ($kbcon > 0) {  # 2018-06-26: if user answers yes-or-no question; 
    KbRetro();   # 2018-06-26: retroactively adjust knowledge base; 
    $kbcon = 0;  # 2018-06-26: reset for safety; 
    $kbzap = 0;  # 2018-06-26: reset for safety.
    return;      # 2018-06-26: abandon remainder of current module.
  }  # 2018-06-26: User has had one chance to answer yes-or-no question.
  $inft = $t;    # 2018-06-26: in case inference-time not otherwise set; 
  if ($becon==1) {  # 2018-01-25: if user input includes 800=BE-verb...
    InFerence(); # 2018-01-25: make a silent inference; 
  }  # 2018-06-26: end of test for input of a be-verb.
  if ($yncon == 1) {  # 2018-06-26: set in the InFerence() module
    AskUser();  # 2018-06-26: for yes-or-no query; 
    return;  # 2018-06-26: abandon the rest of EnThink()
  }  # 2018-06-26: end of test to trigger asking a question.
  Indicative();    # 2017-11-29: default grammatical mood for thought. 
  if ($conj > 0) { Indicative() }  # 2019-01-20: concatenate ideas; TEST
  if ($dunnocon==1) { $dunnocon = 0; return }  # 2018-10-08: only one sentence.
# Subjunctive();   # 2017-11-29: possible future module for grammatical mood.
# Interrogative(); # 2017-11-29: possible future module for grammatical mood.
# ConJoin();       # 2018-09-12: Output one more idea with sufficient activation. 
# ConJoin();       # 2019-01-20: Call ConJoin() from elsewhere; TEST
  if ($etc > 1) {  # 2019-03-02: if multiple thoughts...
    ConJoin();     # 2019-01-20: insert a conjunction;
    Indicative();  # 2019-01-20: include a conjoined idea.
  }  # 2019-01-20: join multiple thoughts together.
  if ($whatcon==1 && $conj > 0) {  # 2018-09-12: for a conjoined idea...
    $whatcon = 0;  # 2018-09-12: reset to prevent run-on thoughts. 
    Indicative();  # 2018-09-12: think in the indicative mood.
    $conj = 0;     # 2018-10-08: prevent run-on sentences.
  }  # 2018-09-12: end of whatcon-test in favor of subordinate clause.
  PsiDecay();      # 2017-11-29: Reduce activation after each thought.
  $conj = 0;       # 2019-01-20: reset; TEST; REMOVE if necessary
  $dunnocon = 0;   # 2019-09-18: reset outside of SpreadAct() to prevent carry-over.
  $etc = 0;        # 2019-03-02: reset the flag that triggers a conjunction.
  $ictus = 0;      # 2018-09-12: prevent build-up.
  $subjnom = 0;    # 2018-07-01: reset outside of InFerence() to prevent interference.
  $whatcon = 0;    # 2019-09-18: reset outside of SpreadAct() to prevent carry-over.
  $tpr = 0;        # 2019-09-24: prevent carry-over?
}  # 2019-03-02: EnThink() returns to Volition().

5. Variables for the EnThink English Thinking Module

$becon -- be-conditional -- carries a flag from the OldConcept() recognition module indicating that new input includes a verb of being which may permit the InFerence() module to make a general inference about the subject of the input so that the InFerence() module can look for prior knowledge as the basis of an inference.

$catsubj -- conCATenated (chained) SUBJect flag for syncopating sentences.

$catverb -- conCATenated (chained) verb flag for syncopating sentences.

$conj -- a dual-purpose variable serving both as an identifier of which particular conjunction is under consideration for use by the ConJoin module, and a control-flag for the decision of whether to call the Indicative module more than once.

$dunnocon -- is a flag used in SpreadAct() to permit an AI Mind to respond to a who+verb+object query with "I DO NOT KNOW" if no correct answer is found.

$etc -- from the abbreviation "etc." from the Latin phrase et cetera, meaning "and other things" -- a counting variable that is incremented in the EnNounPhrase() module when more than one fetchable idea is active in conceptual memory. The $etc count is used in the EnThink() module as a trigger for calling the ConJoin() module to insert a conjunction like "and" between two ideas in the generation of a sentence of thought.

$gapcon -- status-con flag for AudInput() to count down gaps of no input, so that internal thinking may accelerate during periods of no input from external sources.

$ictus -- testable activation-level to trigger use of a conjunction by the ConJoin() module in expressing a compound thought composed of two or more strongly activated ideas, each generated by a single calling of the Indicative() module.

$isolation -- counter of thought-cycles spent in "isolation" with no human input, as an arbitrary trigger for output by the AI Mind, or as a threshold for the AI to take certain actions if input suddenly appears.

$kbcon -- knowledge-base-condition flag for KbRetro to wait for a yes-or-no answer.

$kbzap -- ZAP the knowledge base -- is a variable that holds the oldpsi word "YES" or "NO" when the InFerence() module has caused the AskUser() module to seek confirmation or denial of a silent inference from a human user engaged in a conceptual conversation with the AI Mind. KbRetro() uses the YES-value kbzap to confirm an inference, or the NO-value of kbzap to negate an inference.

$nucon -- new-condition – segregates SpreadAct() code to respond to the input of an unknown word by asking the user a question about the new concept being learned by the AI Mind.

$output -- output string as in JavaScript FirstWorkingAGI.html

$pov -- point-of-view: 1=self; 2=dual; 3=alien. When pov=1, the word "you" is somebody in the external word. When pov=2, the word "you" refers to the self-concept "I" in the AI. When pov=3, the word "you" is interpreted as part of a conversation by a third-party or as a word in a text, not referring to the self-concept of either the AI or of someone talking to the AI.

$qucon -- query-condition – segregates SpreadAct() code to respond to the input of who-queries.

$subjnom -- subject nominative – is a concept identified in the OldConcept() recognition module as the subject of an input causing the AI to make an inference.

$whatcon (what-condition) -- SpreadAct() flag for condition of answering a what-query

$wherecon (where-condition) -- flag for condition of answering a where-query.

6. Troubleshooting and Debugging for AI Mind Maintainers

6.1.a. Symptom: (Something goes wrong.)
6.1.b. Solution: (AI Mind Maintainer devises solution.)

7. Future Development