Re: My talk about Godel to the post-grads.

On Sun, 06 Jul 2008 19:39:41 +0100, John Jones <jonescardiff@xxxxxxx>
wrote:

David C. Ullrich wrote:
On Sat, 05 Jul 2008 20:04:48 +0100, John Jones <jonescardiff@xxxxxxx>
wrote:

David C. Ullrich wrote:

You _really_ don't know what the union of two sets is?
A 'union of sets' isn't anything. You can take that as a fact - in all
possible contexts. What's the union of a set of cutlery and a bouquet?

It's irrelevant, since neither is a set in the current sense.

Your contempt for plain thinking is leading you to accept logical
platitudes as fact.

Fascinating.

I'll give you a hint: If A and B are sets then the union of A and
B is the set of all x such that x is an element of A or x is an
element of B.

[Lets ignore the fact that a "set of all ...." is simply "all".]

Erm, that's not a fact. The set of all real numbers is one thing;
all real numbers _are_ many things.

Your definition is either wrongly transcribed or just wrong. It should
read: If A and B are sets then the union of A and all other sets, and
the union of B and all other sets is the set of all x such that x is an
element of A or x is an element of B.

My gosh, you honestly don't know what the union of two sets is.

(In standard set theory there's no such thing as the union of
A and all other sets, by the way. Not that that's directly
relevant - I gave the definition of "the union of A and B"
and your correction is simply funny.)

That's a "logical platitude"? Knowing that is showing
"contempt for plain thinking"?
David C. Ullrich

"Understanding Godel isn't about following his formal proof.
That would make a mockery of everything Godel was up to."
(John Jones, "My talk about Godel to the post-grads."
in sci.logic.)

David C. Ullrich

"Understanding Godel isn't about following his formal proof.
That would make a mockery of everything Godel was up to."
(John Jones, "My talk about Godel to the post-grads."
in sci.logic.)
.

Relevant Pages

  • Re: My talk about Godel to the post-grads.
    ... how can a union be a union of A AND B? ... Address the objection. ... goes around the Sun, ... "Understanding Godel isn't about following his formal proof. ...
    (sci.logic)
  • Re: AREA
    ... union of D_1 and D_2. ... meaningless as you always assumed. ... That would make a mockery of everything Godel ... "expanding f" at other ...
    (sci.math)
  • Re: My talk about Godel to the post-grads.
    ... IF a union of A and B is described only in terms of either A or B, ... "Understanding Godel isn't about following his formal proof. ... (John Jones, "My talk about Godel to the post-grads." ...
    (sci.logic)
  • Re: My talk about Godel to the post-grads.
    ... David C. Ullrich wrote: ... Either A or B is irrelevant in the formation of a union in which only either A or B has elements in common with x. ... "Understanding Godel isn't about following his formal proof. ...
    (sci.logic)
  • Re: My talk about Godel to the post-grads.
    ... how can a union be a union of A AND B? ... Address the objection. ... goes around the Sun, ... "Understanding Godel isn't about following his formal proof. ...
    (sci.logic)