TODO

Reading-list TODO:
------------------

* Russ Harmer and Eugenia Oshurko "Reversibility and composition of
  rewriting in hierarchies", (2020)
  https://hal.archives-ouvertes.fr/hal-02869865

  The idea here is that sequences of rules can be applied, and then they
  can be reversed. This enableds back-tracking on a rule system.

* Scott Garrabrant, Tsvi Benson-Tilsen, Andrew Critch, Nate Soares,
  Jessica Taylor "Logical Induction" (2016) 
  https://arxiv.org/abs/1609.03543

  "We present a computable algorithm that assigns probabilities to
  every logical statement in a given formal language, and refines
  those probabilities over time."

Others:
 * Constructible Duality Logic, Anna Patterson
   PhD thesis

 * algeraic mind 1996 Science paper

 * Programming with galois connections

 * Andre Joyal on simplex category dualities
   https://ncatlab.org/nlab/files/JoyalThetaCategories.pdf

 * http://people.csail.mit.edu/jiex/papers/robogrammar/index.html

 * http://moghs.csail.mit.edu/

 * https://en.wikipedia.org/wiki/Modelica


Writing TODO
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* Logical negation corresponds to vector space complements.
  For example, King-Man+Woman should be interpreted as linear logic,
  and NOT as set theory intersection, subtraction, union operations.

* The voting/club-membership algo in the learn project performs
  generalization.

Coding TODO
-----------
* Remove GROUP_LINK from pattern matcher; this can be done with
  a GROUP_VALUE, instead. See SORT_VALUE for an example. This will
  maintain ultiple sub-lists, grouping inserted items into one of
  the sublists.

* Remove ALWAYS_LINK from pattern matcher. Same idea as above:
  just use ALWAYS_VALUE, modelled on SORT_VALUE, that will turn
  into an empty set if all the items in it are not all the same.

* Have some global thread pool or thread manager? Some way of
  observing threads? Maybe killing them?