Subject: Re: compatibility and the OSD
From: John Cowan <jcowan@reutershealth.com>
Date: Wed, 22 Sep 2004 17:06:18 -0400

Russell Nelson scripsit:

> OSD#3 says "The license must allow modifications and derived works."
> It doesn't say "The license must allow some modifications and derived
> works."  Neither does it say "The license must allow all modifications
> and derived works."  We, however, behave as if it says the latter, not
> the former.  Any reason why we shouldn't?

We don't behave that way.  We call the GPL an open-source license,
though it does not permit *every* sort of derivative work to be made.
(In particular, you cannot modify a GPLed work such that it makes use of
patented technology for which no RF license is available.)

More generally, when we see a general term in a permissive statement
without a quantifier, we infer "some" rather than "all".  For example,
when we see a sign "GOOBERS FOR SALE" we read this as "SOME GOOBERS
FOR SALE", not as "ALL GOOBERS FOR SALE".

-- 
John Cowan  jcowan@reutershealth.com  www.ccil.org/~cowan  www.reutershealth.com
I must confess that I have very little notion of what [s. 4 of the British
Trade Marks Act, 1938] is intended to convey, and particularly the sentence
of 253 words, as I make them, which constitutes sub-section 1.  I doubt if
the entire statute book could be successfully searched for a sentence of
equal length which is of more fuliginous obscurity. --MacKinnon LJ, 1940