gnu-misc-discuss
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Open source - Free software


From: Immortalist
Subject: Re: Open source - Free software
Date: 27 Sep 2006 11:57:55 -0700
User-agent: G2/1.0

Why Tea wrote:
> >
> > How about this: Free software is a subset of open source software, so
> > all free software is open source.
>
> This doesn't sound right. I don't think neither one is the subset of
> the other.
>
> If freeware is a subset of Open Source, then all freeware is Open
> Source. That's clearly NOT the case, is it?

Aside from difference on the meaning of "freeware" and "free software"
some freeware is open source code and some is not-open source code,
therefore it is not the case that all freeware is open source. Possibly
all not-open source code is not freeware but some non-open-source code
is freeware to, hence;

Everyone is familiar with the concept of a necessary condition. For
example, we all know that air is necessary for (human) life. Without
air, there is no (human) life. Similarly, a microscope (or some other
instrument) is necessary for human beings to see viruses. (Viruses are
too small to be seen by the naked eye.)

Similarly, everyone is familiar with the concept of a sufficient
condition. For example, it suffices (i.e. it is sufficient for) an
object's having four sides that it is a square. Or, again, it is
sufficient for your having something to drink that you have a glass of
Coca-Cola®.

http://www.sfu.ca/philosophy/swartz/conditions1.htm

---------------------------------

 Definition: A necessary condition
 for some state of affairs S is a
 condition that must be satisfied
 in order for S to obtain.

For example, a necessary condition for getting an A in this course is
that a student hand in a term paper. This means that if a student does
not hand in a term paper, then a student will not get an A, or,
equivalently, if a student gets an A, then a student hands in a term
paper.

 Definition: A sufficient condition
 for some state of affairs S is a
 condition that, if satisfied,
 guarantees that S obtains.

For example, a sufficient condition for getting an A in this course is
getting an A on every piece of graded work in the course. This means
that if a student gets an A on every piece of graded work in the
course, then the student gets an A.

Handing in a term paper is not a sufficient condition for getting an A
in the course. It is possible to hand in a term paper and not to get an
A in the course.

Getting an A on every piece of graded work is not a necessary condition
for getting an A in the course. It is possible to get an A in the
course even though one fails to get an A on some piece of graded work.

http://philosophy.wisc.edu/hausman/104/nec-suf.htm

------------------------------

A handy tool in the search for precise definitions is the specification
of necessary and/or sufficient conditions for the application of a
term, the use of a concept, or the occurrence of some phenomenon or
event. For example, without water and oxygen, there would be no human
life; hence these things are necessary conditions for the existence of
human beings. Cockneys, according to the traditional definition, are
all and only those born within the sound of the Bow Bells. Hence birth
within the specified area is both a necessary and a sufficient
condition for being a Cockney.

Like other fundamental concepts, the concepts of necessary and
sufficient conditions cannot be readily specified in other terms. This
article shows how elusive the quest is for a definition of the terms
"necessary" and "sufficient", indicating the existence of systematic
ambiguity in the concepts of necessary and sufficient conditions. It
also shows the connection between puzzles over this issue and
troublesome issues surrounding the word "if" and its use in conditional
sentences.

1. Philosophy and Conditions
2. The Standard Theory: Truth-functions and Symmetry
3. Further Problems for the Standard Theory
4. Inferences, Reasons for Thinking and Reasons Why
5. Modest Conclusion

http://plato.stanford.edu/entries/necessary-sufficient/

---------------------------------

 http://www.google.com/search?hl=en&lr=&q=contingency+necessity



reply via email to

[Prev in Thread] Current Thread [Next in Thread]