README for LLP
				1996/11/14 written for version 0.40
				1996/12/09 revised for version 0.41
				1997/05/04 revised for version 0.42
				1998/04/01 revised for version 0.43
				2001/01/23 revised for version 0.50
				2002/04/19 revised for version 0.51

LLP: a linear logic programming language and its compiler system

The language LLP is a logic programming language based on
intuitionistic linear logic.  LLP is a superset of Prolog and a subset
of Lolli which is another linear logic programming language developed
by Hodas and Miller (see http://www.cs.hmc.edu/~hodas/research/lolli/).

LLP is distributed as free software for non-profit use.

	WWW:    http://bach.cs.kobe-u.ac.jp/llp/
		http://kaminari.scitec.kobe-u.ac.jp/PrologCafe/

Any comments and suggestions are welcome!

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REQUIREMENTS

You need the following systems to use LLP compiler.

* ANSI C compiler
  Abstract machine emulator is written in ANSI C.
  I am using GNU C compiler version egcs-2.91.66.

* Prolog system
  Prolog system is used to compile LLP program into abstract
  machine code.
  I am using
  - SICStus Prolog version 3.7.1
    (commercial, see http://www.sics.se/ps/sicstus.html).

  You don't need Prolog if you only execute example programs
  included in the package (they are already compiled).

  See also http://kaminari.scitec.kobe-u.ac.jp/PrologCafe/,
  if you want LLP to Java translator.

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INSTALLATION

* Unzip and untar the distribution file
	% zcat llp051.tar.gz | tar xvf -

  Directory named llp051 will be created.

* Make symbolic link for further set-up.
	% ln -s llp051 llp
	% cd llp

* Edit Makefile to meet your machine architecture
  Currently, LLP can run on Linux and Solaris.

* Edit Makefile to select your Prolog system.
  $PROLOG and $PSYSTEM are referred in 'comp_pl' program,
  which is used at installation procedure.

* Set PATH and LLPDIR
	% set path = (~/llp/bin $path)
	% rehash
	% setenv LLPDIR ~/llp

* Make the system
	% make

* If you use Emacs, append the following lines to .emacs file.

	;;;
	;;; LLP
	;;;
	(setq load-path
	      (cons (expand-file-name "~/llp/lib") load-path))
	(setq auto-mode-alist
	      (cons '("\\.llp$" . llprolog-mode) auto-mode-alist))
	(autoload 'run-llprolog "llprolog"
	  "Start a LLProlog sub-process." t)
	(autoload 'llprolog-mode "llprolog"
	  "Major mode for editing LLProlog programs" t)

  You can use the following key commands in llprolog-mode.

	C-c K		compile the buffer
	C-c k		compile the region
	C-c C-k		compile the predicate

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HOW TO USE

Some example programs are in "examples" directory.
	% cd ~/llp/examples/llp
	% llp queens

You can also use Small LLP interpreter.
	% cd ~/llp/examples/llp
	% llp
	Small LLP Interpreter
	| ?- load(queens).
	| ?- main.

To run java interface, you need to have JDK.
	% cd ~/llp/tools/java
	% java Queens
	% java Pentomino

Since Process class is system dependent feature of Java, the program
might not work well on your machine.  I checked the program on Java
version 1.2.2 on Linux.

To compile your program, please use "llprun" command.
	% llprun file		/* to compile & run */

The "llprun" command executes the following.
	% llpc file	"file.llp" is compiled into 
			LLPAM binary code "file.llpo".
	% llp file	"file.llpo" is executed with built-in predicates
			defined in built.llpo, inout.llpo, and llpi.llpo.

Your program should include main/0 predicate as the start point
(you can change the entry predicate by -e option).

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LIMITATIONS

* No debugging aids.
  Small interpreter system with tracing facilities is available.

* Few built-in predicates (see BUILTINS).

* No garbage collectors.
  You need to edit "llpam.h" file to enlarge data areas.

* No optimizations (register allocation, environment trimming,
  last-call-optimization).

* No floating point numbers, integer is 28 bits signed.

* Nesting of & and ! goals are limited to 2^27-2.

* What are limited compared with Lolli.
  - Universal quantifiers can not be used in G-formulas and R-formulas.
  - Compound formulas can not be used in clause heads.
  - No modules
  - Syntax is different
    (operator precedences are defined same as much as possible)

	Lolli			LLP
	true			true
	erase			top (You can also use erase)
	{P}			!P
	P, Q			P, Q
	P & Q			P & Q
	P ; Q			P ; Q
	P -o Q			P -<> Q
	P :- Q			P :- Q
	P => Q			P => Q
	P <= Q			Q => P
	forall x \ P		forall [X] \ P
	exists x \ P		(not available)
	top (top level loop)	(not available)

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KNOWN BUGS

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DOCUMENTS

Summary of built-in predicates can be found in:
	BUILTINS

Technical papers related to LLP can be found at:
	http://bach.cs.kobe-u.ac.jp/llp/papers/

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FUTURE PLANS

This space is too narrow to write all of my hopes...

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CHANGES

See CHANGES file.

--
Naoyuki Tamura 
Department of Computer and Systems Engineering
Faculty of Engineering, Kobe University
1-1 Rokkodai, Nada, Kobe 657-8501 Japan
E-mail: tamura@kobe-u.ac.jp
WWW: http://bach.cs.kobe-u.ac.jp/tamura.html

Mutsunori Banbara
Nara National College of Technology
E-mail: banbara@kaminari.scitec.kobe-u.ac.jp
WWW: http://kaminari.scitec.kobe-u.ac.jp/~banbara/