[erlang-questions] A PropEr announcement

Edmond Begumisa <>
Fri Jun 17 04:56:59 CEST 2011


Just to clarify/reinforce, what gets a little confusing in these  
discussions are the rights and obligations between licensor and licensee,  
which is a contractual arrangement and subject to the doctrine of privity.

[Continuing with the mentioned hypothetical]

* If the PropEr developers have copies of QuickCheck Mini, then they bind  
themselves to a license agreement with Quviq, including the promise not to  
reverse engineer.
* If PropEr is GPL'ed, and Vlad uses it, he binds himself to an agreement  
with the PropEr developers, and the terms thereunder.

Vlad is not privy to the first agreement, and thus can never be held  
liable for its breach, if there is such a breach. And he cannot be  
expected to stop using a version he already has. (Though he might have the  
rug pulled out from under him, should PropEr development cease and future  
versions stop being made.)

However, assuming all parties are in Europe, and although the concept of  
freedom of contract generally applies, they also bind themselves doctrine  
that they can never make an agreement that contravenes codified EU law -  
including said reverse-engineering law in said copyright statute. Then the  
aggrieved party need not be privy to an agreement to have their rights  
enforced since these rights are not established by an agreement, but by a  
statute. In this case, Vlad and all PropEr users in Europe could well be  
ordered by a court to cease using the program regardless of any agreement  
they have with it's developers (since such an agreement would be  
considered invalidated.) Hypothetically speaking.

That said: Erlang being a small-friendly community -- I assumed (and like  
to continue to a assume) that PropEr and QuickCheck developers have not  
only been aware of each others projects, but I also like to think that  
they've been in touch with each other and sorted out any such concerns  
before version 1 of PropEr was announced. Like Erlang, I prefer to think  
of the happy case!

- Edmond -


On Thu, 16 Jun 2011 18:23:04 +1000, Ulf Wiger  
<> wrote:

>
> On 16 Jun 2011, at 10:01, Vlad Dumitrescu wrote:
>
>> On Thu, Jun 16, 2011 at 08:43, Ulf Wiger  
>> <> wrote:
>>
>> On 16 Jun 2011, at 08:30, Vlad Dumitrescu wrote:
>>
>>> Hi,
>>>
>>> This kind of issues are worse than flame wars! :-)
>>>
>>> I have yet another point of view that increases the confusion: PropEr  
>>> is mostly compatible with Triq and QuickCheck (there's a free older  
>>> version).
>>
>> Well, there is a version available in jungerl, but to my knowledge, it  
>> was not put there by the authors, and not actually intended to be free.  
>> Even so, one might consider it a lot less sensitive to copy that  
>> version than the later, proprietary, versions of QuickCheck.
>>
>> Quviq released an official mini-version last year.
>>
>> http://www.quviq.com/news100621.html
>
> Yes, but the QuickCheck Mini license agreement, while permitting free  
> use and re-distribution, specifically forbids reverse-engineering. Thus,  
> we should hope that the PropEr developers did not obtain a copy of  
> QuickCheck Mini and ran it in order to learn how it worked, as this  
> would put them in violation of the EU Directives regarding software  
> copyright.
>
> For those who are inspired by PropEr, but are put off by the GPL, using  
> and re-distributing QuickCheck Mini is of course unproblematic. ;-)
>
> BR,
> Ulf W
>
> Ulf Wiger, CTO, Erlang Solutions, Ltd.
> http://erlang-solutions.com
>
>
>


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