License agreement

[Das deutsche Original haben Sie zusammen mit dieser Uebersetzung erhalten.
You have received the German original together with this translation.]

Preamble

The aim of this license agreement is to enable the free use of the
software that is described in the sequel by anyone. In order to
guarantee this, it is necessary to set up rules for the use of the
software that hold for any user.

Provider of this license is the University of Bremen, represented by
its principal (called "license provider" in the sequel). The provider
of the license has developed the "Heterogeneous Tool Set" (Hets, just
called "software" in the sequel). The software consists of a command
line tool for the analysis of specifications and a graphical interface
for the management of specifications and proofs using development
graphs.

Following the ideas of open source software, the license provider
gives access to the software without fee for anyone (called "license
taker" in the sequel) under the following conditions which are similar
to the Lesser Gnu Public License (LGPL). Each license taker obligates
himself to follow the terms of use below.


Paragraph 1 Principle

Each license taker appreciating these terms of use receives a simple
right, not restricted in time and space and without any fee, to use
the software, in particular, to copy, distribute and process
it. Exclusively the following terms of use do hold.  The license
provider explicitly contradicts any conflicting terms of business. By
making use of the rights described below, in particular by copying or
distributing it, a license treaty between the license provider and the
license takes is concluded.


Paragraph 2 Copying

The license taker has the right to make and distribute unmodified
copies of the software on any media. Prerequisite for this is that the
license provider and this license agreement is clearly recognizable,
and that the sources are distributed together with the software.


Paragraph 3 Modification and Distribution

The license taker has the right to modify copies of the software (or
parts thereof) and to distribute these modifications under the terms
of Paragraph 2 above and the following conditions:

1. The modified software has to carry a clear mark that points to the
original license provider, the modification that has been made, and
the date of the modification.

2. The license taker has to ensure that the software as a whole or
parts of it are accessible to third parties under the terms of this
license agreement without fee.

3. If during the modification a copyright of the license taker
emerges, then this copyright must be put under the terms of this
license if the modified software is distributed.


Paragraph 4 Other duties

1. Reference to the validity of this license agreement must not be
modified or deleted by the license taker.

2. The use of the software by third parties must not be conditioned by
the fulfillment of duties that are not mentioned in this license
agreement.

3. The use of the software must not be prevented or complicated by
means of technical protection, in particular copy protection means.


Paragraph 5 Liability, Update

1. Liability of the license provider is restricted to fraudulent
withheld factual or legal errors. The license provider does not give
any warranty, and neither ensures any properties of the
software. Furthermore, he is liable only for those damages that are
caused by willful or grossly negligent violation of duty.

2. The license provider has the right to update these terms of use at
any time.


Paragraph 6 Forum for users

The license provider does provide neither support nor
consultation. Without acknowledgment of any legal duty, the license
provider will care about the installation of a user forum for
discussions about the software and its further development.


Paragraph 7 Legal domicile

It is agreed that the law of the Federal Republic of Germany is valid
for this license agreement. For any lawsuits or legal actions emerging
from this license agreement, it is agreed that exclusively German
courts are competent. Legal domicile is Bremen.


Paragraph 8 Termination through Offense

Any violation of a duty of this agreement automatically terminates the
rights of use of the offender.


Paragraph 9 Salvatorian Clause

If any rule of this agreement should be or become inoperative,
validity of the other rules is not affected. The parties will care
about replacing the invalid rule by some valid rule that comes close
to the purpose of this agreement.