About

Adaptation in Clojure of W.Byrd's and Co. paper about µKanren (microKanren) - a subset of miniKanren focused on core relational programming operators and devoid of functions pertaining rather to the end-user's purview.

101 on µKanren

A microKanren program is a sequence of goals , each goal can either succed or fail. The result of a µKanren program is a stream of satisfying states, i.e. such that make succed all goals.

Goals constructors

In µKanren there are 4 primitive goal constructors:

• unification constructor: ===

  ;; the goal `succeds` if A is `unified` with B
  (=== A B)

• binary conjunction: conj

  ;; .. of the goals A and B, resulting in a goal that succeds if both A and B succed
  (conj 
     A
     B)

• binary disjunction: disj

  ;; .. of the goals A and B, resulting in a goal that succeds if either A or B succeds
  (disj 
     A
     B)

• operator fresh:

  ;; creates a fresh (i.e. new) logic variable X
  ;; accepts unary function fn_X: i.e. fn[X]( expression_with_X)
  ;; where variable X is a fresh logic variable bound to 
  ;; expression_with_X expression,
  ;; expression_with_X evaluates to a goal.
  (fresh fn_X)

Useful scripts

• install clojure-cli

  $ curl -L -O https://github.com/clojure/brew-install/releases/latest/download/linux-install.sh  \
      chmod +x linux-install.sh  \
      sudo ./linux-install.sh

• run

  $ clj -M -m microkanren.main