-*- mode:Text -*-
Copyright 1992 Patrick H. Winston.  All rights reserved.
Version 1.1, transferred from master disk on 21 Jan 93
 
This file may reference other files containing copyrighted software.
Any restrictions on the use of such software are described in the
files containing that software.  This file may be freely copied as
long as this notice is kept intact.

PURPOSE

Provides program support program support for Chapter 12, Symbolic
Constraints and Propagation.
Illustrates constraint propagation using time intervals.

PERFORMANCE EXPERIMENT 1

Examine the file time.exp.  Run the search experiments by
typing the following command to your lisp system:

(load "time.exp")

Alternatively, evaluate each Lisp expression in the file one at a
time, noting what each does.

PERFORMANCE EXPERIMENT 2

Run the time constraint-propagation procedure with other time
nets.

SMALL-SCALE LISP PROJECT

Delete the propagation steps in the procedure that establishes
surviving labels.  Then implement a mechanism that does
propagation by applying the label-constraining procedure to all
node triples.

MEDIUM-SCALE LISP PROJECT

Implement a mechanism for propagating time constraints along
reference nodes.