User's Manual
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price. Our General Public Licenses are designed to make sure that 
you have the freedom to distribute copies of free software (and 
charge for this service if you wish), that you receive source code or 
can get it if you want it, that you can change the software or use 
pieces of it in new free programs; and that you know you can do 
these things.
To protect your rights, we need to make restrictions that forbid 
anyone to deny you these rights or to ask you to surrender the 
rights. These restrictions translate to certain responsibilities for 
you if you distribute copies of the software, or if you modify it.
Forexample,ifyoudistributecopiesofsuchaprogram,whether
gratis or for a fee, you must give the recipients all the rights that 
you have. You must make sure that they, too, receive or can get 
the source code. And you must show them these terms so they 
know their rights.
We protect your rights with two steps: (1) copyright the software, 
and (2) oer you this license which gives you legal permission to 
copy, distribute and/or modify the software.
Also, for each author’s protection and ours, we want to make 
certain that everyone understands that there is no warranty for 
this free software. If the software is modied by someone else and 
passed on, we want its recipients to know that what they have is 
not the original, so that any problems introduced by others will 
not reect on the original authors’ reputations.
Finally, any free program is threatened constantly by software 
patents. We wish to avoid the danger that redistributors of a free 
program will individually obtain patent licenses, in eect making 
the program proprietary. To prevent this, we have made it clear 










