The usage of the descartes language 

 The license of the descartes language 
 This program is free software;  you can redistribute it and/or modify 
 it under the terms of the GNU General Public License as published by 
 the Free Software Foundation;  2, either version or(at your option) 
 any later version. 


1.  Start method 

1.1  Start with an argument. 

   Set a program file as an argument. 

     $ descartes example 


   Descartes read program file "example" and carry it out. 


1.2  Start without an argument. And it is started Command Prompt.

   Command Prompt is displayed when it starts without an argument. 

     $ descartes 
     0.1.0 Descartes Copyright(C)  2009 Hideyuki Niwa 

     ? 


   "?" is displayed to a prompt and carries out input descartes 
   language program. 
   You can use the "load" predicate to load a program. 

   This is an example carrying out the "append" program. 

     ? <load "append">;

   Only Command Prompt can omit the outside parenthesis. 

     ? load "append";

     result - - 

     (Load "append") 
     - - true 

     ? append #x (a b) (c); 

     result - - 

     (append (a b c) (a b) (c)) 
     - - true 


2.  The stop method of the Command Prompt 

   Use the "quit" predicate, and to stop. 

     ? quit; 


3.  The path of the program file 

   The library and program of the Descartes language are looked for 
   from the place where the DLIBPATH environment variable is specified.
    The path of DLIBPATH is divided by COLON":". (The Windows version is 
   divided by SEMICOLON";")

    Even if the library or program in the directory specified 
  by DLIBPATH do not specify a path, they are executed as 
  a specification program of the argument of descartes, and 
  load and an include predicate.

   The specification method of the environment variable DLIBPATH 
  should follow the setting method of the environment variable of OS.


   A specification method in bash of Linux: 
     Export DLIBPATH="/usr/local/lib/descartes:. " 

   By Windows, please set "environment variable" of the 
   property of the system in Control Panel. 


