ERGO

This is a distribution of software that comes with the book Programming Cognitive Robots by Hector Levesque. It comes with absolutely no guaranties or support. Also, do read the copyright notice.

This directory contains all the files and directions for running the ERGO system as well as a number of ERGO programs. It contains the following:

README.txt: This file
history.txt: A list of updates and fixes to the software
ergo-sheet.pdf: A one page summary of the ERGO system
install.txt: Instructions on installing ERGO
System/: All the system files
Examples/: Some example ERGO programs
Projects/: Three larger ERGO programs
Servers/: Programs to be run in conjunction with ERGO

Each subdirectory will contain its own explanatory README file.

The original collection of files was put together on March 17, 2019.

This describes how to setup and run the ERGO system.

INSTALL

INSTALLATION OF RACKET

See http://racket-lang.org/. You can test that things are working with

> racket -e '(+ 3 4)'
7

INSTALLATION OF ERGO

First, put all the files in the Ergo/System/ directory somewhere convenient, away from user ERGO programs. On a Mac, a reasonable choice is to create ~/Library/Application Support/Ergo/ and put them there.
Then find out where Racket keeps user-defined collections. It's the first element of "(current-library-collection-paths)".

In Mac:
```
> racket -e '(car (current-library-collection-paths))'
#<path:/Users/hector/Library/Racket/7.2/collects>
```
In Linux:
```
$ racket -e '(car (current-library-collection-paths))'
#<path:/home/ssardina/.racket/7.2/collects>
```
Note: if Racket is updated, the version folder (7.2/ above) will change, so it needs to be updated manually.
Create the user /path/to/collects/ directory from (2) if needed, and a new subdirectory inside it called "ergo".
Put a file called main.ss in the ergo/ directory from step (3). It should contain just the following three lines:
```
(module main racket
(require (file "/path/to/implementation/full-system.scm"))
(provide (all-from-out (file "/path/to/implementation/full-system.scm"))))
```
where the /path/to/implementation/ is the directory from step (1) above.

Test that ERGO is correctly installed:

> racket -l ergo -e '(ergo-do :nil)'
    Loading ERGO v1.5 (Feb 2021) in Racket 7.2 ...
'()

RUNNING ERGO

(and do see Chapter 2 of the book)

To access ERGO interactively:
```
$ racket -l ergo -i
```
From there, the primitive functions like define-fluents and ergo-do can be used. Files containing other definitions can be loaded with include.
To run interactively after loading an ERGO file myfile.scm:
```
$ racket -l ergo -i -f myfile.scm 
```
Other files can be loaded using "include" within myfile.scm.

To load an ERGO file Examples/lift-table.scm and then evaluate (main)

$ racket -l ergo -f Examples/lift-table.scm -m
Loading ERGO v1.5 (Mar 2018) in Racket v6.11 ...
Loading on demand /home/ssardina/git/soft/agents/ERGO.git/System/ergo-do.scm
'((grab! r1 e1)
  (lift! r1 1)
  (grab! r2 e2)
  (lift! r2 1)
  (lift! r2 1)
  (lift! r1 1)
  (lift! r1 1)
  (lift! r2 1)
  (lift! r2 1)
  (lift! r1 1)
  (lift! r1 1)
  (lift! r2 1)
  (lift! r2 1)
  (lift! r1 1))

To load an ERGO file myfile.scm and then evaluate an expression expr:
```
$ racket -l ergo -f myfile.scm -e 'expr'
```

To load an ERGO file reactive-elevator-run.scm and run the program control:

$ racket -l ergo -f Examples/reactive-elevator-run.scm -e "(ergo-do control)"
   Loading ERGO v1.5 (Mar 2018) in Racket v6.11 ...
Loading on demand /home/ssardina/git/soft/agents/ERGO.git/System/ergo-do.scm
'(down! down! down! down! turnoff! up! up! turnoff! down! down! down! down!)

ssardina/ergo

ERGO

INSTALL

INSTALLATION OF RACKET

INSTALLATION OF ERGO

RUNNING ERGO