;;; ~/my-domains/jobsite/domain.lisp
;;;
;;; AUTHOR : Bruce LeSourd
;;;          c473ak
;;;
;;; DATE   : 5/12/91
;;;
;;; PROJECT - domain description

CONSTRUCTION JOB-SITE PLANNER

	Attempts to solve the problem of planning the initial phases
of a large steel-frame construction project (e.g. a skyscraper):

	1.  foundation and sub-floor excavation;
	2.  framing;
	3.  slab pours.

The job-site is always flat and orthogonal, consisting of "cells"
defined by grid lines and floors.  Resources (materiel and people)
arrive at the job-site edges on floor 0.  The project has a deadline
and a budget which constrain construction scheduling.

NOTES ON THIS VERSION:

	This version is inoperable, but it gives a good idea of the
operators necessary for jobsite planning.  The searches generated
in this domain are truly massive, and encoding enough simple knowledge
in search control rules to solve even toy problems is proving difficult.
For example, one of the main common-sense principles in jobsite planning
is "leave time to build floor 1 before you build floor 2".  One solution
to this problem, where the STATE backtracks along with Prodigy (resources
end offsite, with one of the goals being to start them offsite), is
investigated, unsuccessfully, in "jobsite2".  However, "jobsite" and
"jobsite2" have some basic bugs, so the validity of their time/space idioms
has not been conclusively verified.

IF YOU WANT TO RUN PROBLEMS, RUN THE "EXC*.LISP" PROBLEMS IN "JOBSITE3"!

HOURS TO CODE: who knows

RELATION TO EXISTING DOMAINS ("jobsite" only):

	JOBSITE has the spatial flavor of GRIDWORLD and the temporal
flavor of SCHEDWORLD.  However, constraining the movements and actions
of multiple resources in both space and time poses a much different
problem than that of either existing domain.  Unlike SCHEDWORLD,
certain operations can take several time units.


IDEAS BORROWED FROM EXISTING DOMAINS:

	JOBSITE borrows the "last-scheduled" concept from SCHEDWORLD.
Whether JOBSITE's use of "last-scheduled" is really analagous to
its use in SCHEDWORLD is questionable.  Both domains use "last-scheduled"
to generate time values, but JOBSITE also uses it to generate locations.





