Add LICENSE file

Add README.md

Remove unnecessary `the`

Add Makefile and samples

Assign most frequently referenced variables first

Code simplification

Remove unnecessary double unassign

Abort on empty clause

Add parser and file input to Main

Fix unassign on backtracking

Remove duplicated implementation for "pure"

Code cleanup

Finish monadic do-conversion

Half-way to monadic do-conversion

Split into core and Main module

Cleanup and define exported interface

Initial commit