# File:		ah/README

# Author:	Ken Friedenbach
# Copyright, 2009-2014. 
# All rights reserved
 
Abstraction Hierarchies are defined in:
	"Abstrction Hierarchies: A Model of Perception and Cognition in the Game of Go",
	K.J. Friedenbach, Ph.D. thesis, University of California, Santa Cruz, 1980.

This project is the sixth attempt to implement the model:
	1. Burroughs Algol, on a Burroughs B5500, 1974-76.
	2. Early C, on a PDP 11/40, 1980. (Friedenbach thesis version)
	3. Mesa, on a XEROX Dorado computer, 1980-81.
	4. Object Pascal, on Apple Lisa and Macintosh, 1981-1988. (Molin thesis version)
	5. C++, on various Apple and workstations, 1988-1992, 2003-2009.
	6. Go, on various Apple Macs, Nov. 2009-2014.

The ah package contains the following files:
    Thesis_no_cover.pdf.zip - scanned Friedenbach thesis in zipped PDF file.
	board.go		- the board level data structures
	comp.go			- functions to compute board point and graph node states
	errors.go		- defines an error handling mechanism
	gostrings.go	- the string level data structures
	graph.go		- graph data structures for higher abstraction levels
	patterns.go		- whole board and partial board patterns of good moves
	trans.go		- transformations (rotations and reflections) of boards
	update.go		- the Go abstraction hierarchy and the update algorithm
	zhash.go		- Zobrist hashing to detect duplicate positions

Note: Githup commits are checked by Travis CL