You are viewing the historical archive of The Philosophy Forum.
For current discussions, visit the live forum.
Go to live forum

TonesInDeepFreeze

['Member']Joined: March 16, 2021 at 22:18Last active: January 25, 2026 at 22:06None discussions3786 comments

Bio

Some of the symbols I use:

~ ... it is not the case that

-> ... implies

<-> ... if and only if

& ... and

v ... or

A ... for all

E ... there exists a/an

E! ... there exists a unique

Axy ... for all x and for all y [for example]

Exy ... there exists an x and there exists a y [for example]

=> ... implies [in the meta-language]

<=> ... if and only if [in the meta-language]

if P(x) is a formula, then, in context, P(y) is the result of replacing all free occurrences of x with y [for example]

= ... equals

not= ... does not equal

< ... is less than

<= ... is less than or equal to

> ... is greater than

>= ... is greater than or equal to

+ ... plus

- ... minus

* ... times

/ ... divided by

^ ... raised to the power of

! ... factorial

e ... is an element of

0 ... the empty set (also, zero)

w ... the set of natural numbers [read as 'omega']

N ... the set of natural numbers

Q ... the set of rational numbers

R ... the set of real numbers

{x | P} ... the set of x such that P [for example]

{x y z} ... the set whose members are x, y and z [for example]

<x y> ... the ordered pair such that x is the first coordinate and y is the second coordinate [for example]

(x y) ... the open interval between x and y [for example]

(x y] ... the interval between x and y, including y, not including x [for example]

[x y) ... the interval between x and y, including x, not including y [for example]

[x y] ... the closed interval between x and y [for example]

| | ... the absolute value of

U ... the union of

P ... the power set of

/\ ... the intersection of

x u y ... the union of x and y [for example]

x n y ... the intersection of x and y [for example]

x\y ... x without the members of y [for example]

c ... the set complement of

1-1 ... bijection

|- ... proves

|/- ... does not prove

|= ... entails

|/= ... does not entail

PA ... first order Peano arithmetic

S ... the successor of

# ... the Godel number of

card ... the cardinality of

Z ... Zermelo set theory

ZC ... Zermelo set theory with the axiom of choice

ZF ... Zermelo-Fraenkel set theory

ZFC ... Zermelo Fraenkel set theory with the axiom choice

Z\I ... Zermelo set theory without the axiom of infinity

(Z\I)+~I ... Zermelo set theory with the axiom of infinity replaced by the negation of the axiom of infinity

Z\R ... Zermelo set theory without the axiom of regularity

ZF\R ... Zermelo-Fraenkel set theory without the axiom of regularity

ZFC\R ... Zermelo Fraenkel set theory with the axiom choice without the axiom of regularity

p ... possibly

n ... necessarily

when needed for clarity, ' ' or " " indicate an expression not its referent ('Sue' is a name, Sue a person)

Favourite Philosopher

Alonzo Church, Steven Wright, Sonny Clark

Favourite Quotations

"Are you chewing gum?"

Comments

Not just populists and prominently egregious demagogues, but also "mainstream conservatives", "center right", Republicans in general, "mainstream libe...
October 09, 2025 at 04:37
Often, both the Left and the Right strenuously attempt to distance themselves from political assailants. So it's hardly notable that many on the Right...
September 29, 2025 at 02:09
In the controversy about Carr and Kimmel, these distinctions are too often overlooked: (1) Governmental action to restrict speech vs private action to...
September 29, 2025 at 01:52
It was not just Bondi, many Republicans, certain MAGAists and Carr, who was appointed by Trump, who aligned themselves with governmental restrictions ...
September 29, 2025 at 01:43
Cruz claims that McCabe publically and repeatedly said that Comey authorized McCabe to leak. McCabe says that he had two people deliver the leak and t...
September 29, 2025 at 01:24
Here's one: Leontiskos insinuated rather than openly stating. To insinuate instead of openly stating is dishonest. Leontiskos has been dishonest. That...
November 20, 2024 at 05:59
Leontiskos: There are people here who think acetone is merely oxygen. TonesInDeepFreeze: I don't think acetone is merely oxygen. Leontiskos: What else...
November 20, 2024 at 05:50
Here's some informal logic that is not "mere symbol manipulation": You said that there are some here who view logic as mere symbol manipulation. So, i...
November 20, 2024 at 05:13
Who did you think fits the bill? It's a simple question.
November 20, 2024 at 04:41
When you wrote, "There are some logicians in these parts who view logic as mere symbol manipulation", who were you referring to? (I meant 'posters' no...
November 20, 2024 at 04:21
But you did order it. You asked for a symbolization to see how the definition of 'valid argument' implies that explosion is a valid argument. I gave y...
November 20, 2024 at 04:15
When you wrote it, you were referring to unnamed posters. Was I one of them or not? Your intent when you wrote it is not affected by anything I say re...
November 20, 2024 at 04:13
You said you asked for a symbolization of the definition for this reason: I gave you symbolizations of (1) the definition of 'valid argument' and (2) ...
November 20, 2024 at 03:48
When you claim, "There are some logicians in these parts who view logic as mere symbol manipulation", do you include me, thereby claiming that I view ...
November 20, 2024 at 03:47
By following the links to the posts, the poster referred to disjunctive syllogism. In that context, what set of premises does Leontiskos think textboo...
November 19, 2024 at 04:55
Leontiskos does not name who he means, so it behooves me to speak for myself. (1) I'm not a logician and (2) I do not regard logic as mere symbol mani...
November 19, 2024 at 04:48
I'll use the notion of 'satisfiable' (there is an interpretation in which all the members the set are true, and 'unsatisfiable' denoting the negation ...
November 19, 2024 at 04:28
The BSer mentioned me in a misleading way, and posted more BS.
November 19, 2024 at 02:14
You asked me a question. I gave you a rigorous detailed answer. What was the purpose of your question? And you would do well to re-read that Wikipedia...
November 18, 2024 at 21:51
This is not sophistry: (1) define 'is an interpretation' (2) define 'is true in an interpretation' (3) define 'is an argument' (4) define 'is a valid ...
November 18, 2024 at 20:55
There is no sophistry in pointing out that that the standard definition of validity implies that any argument with an inconsistent set of premises is ...
November 18, 2024 at 20:34
Yes. But why do you ask, unless you'll read one?
November 18, 2024 at 20:26
You linked to my post about disjunctive syllogism.
November 18, 2024 at 20:18
Disjunctive syllogism is in lots of textbooks. You're ridiculous.
November 18, 2024 at 20:11
What I've said is correct, not merely because I said it.
November 18, 2024 at 20:11
Oh come on! Get a textbook that uses disjunctive syllogism. You won't even look at a textbook yet you are challenging me to cite one! Not playing your...
November 18, 2024 at 20:06
It's not a matter of what I "regard" to be the case.
November 18, 2024 at 20:06
The rule is completely unambiguous: If P v Q is on a line, and ~P is on a line, then we may put Q on a new line. Or better, without "we", "may" and "p...
November 18, 2024 at 19:53
In this case: We have the premise P & ~P. We want to get P v Q and we want to get ~P, so we can apply disjunctive syllogism to get Q. We get P v Q by ...
November 18, 2024 at 19:49
(1) In no interpretation are both A and ~A true. (2) Having A & ~A as a premise, thus being able to have A as a line and ~A as a line, does not vitiat...
November 18, 2024 at 19:44
The definition involves quantification, so I wouldn't reduce it to a merely sentential formula.
November 18, 2024 at 19:40
I adduced it as a previously proven theorem to help you see how the final step would by an application of modus ponens, so you'd have another way to l...
November 18, 2024 at 19:39
That is not a rendering of my formulation.
November 18, 2024 at 19:33
Here's how I would write it: 1. P & ~P (premise) 2. P (from 1, conjunction elimination) 3. P v Q (from 2, disjunction introduction) 4. ~P (from 1, con...
November 18, 2024 at 19:16
First, why do you ask? The statement you seem to have in mind is: (1) It is not the case that there is an interpretation in which all the premises are...
November 18, 2024 at 18:41
Again, below is what obtains in ordinary formal logic, regardless of any inclinations I might have or not have toward what the definitions or results ...
November 18, 2024 at 18:06
(1) Contrary to Leontiskos, I am not "disingenous" in this discussion. No statement of mine, about Michael or anything else, has been shown to be dish...
November 18, 2024 at 17:52
I don't see how this cannot be understood. From the definition of validity, we show that the principle of explosion is valid. Then, if an argument has...
November 18, 2024 at 08:19
I didn't give an "interpretation" of the definition. I stated the standard definition. The definition doesn't make "recourse" to the principle of expl...
November 18, 2024 at 07:24
Again, I'm not interested, at this juncture, in untangling Michael's role. I am especially not interested in commenting on his posts vis-a-vis you in ...
November 18, 2024 at 07:06
I've addressed the subject of this thread in detail. My intellectual credibility does not require that I sort through your own disagreements with a po...
November 18, 2024 at 06:58
I don't know what passages you're referring to. You've not shown that anything I've said is incorrect. Your picture of this thread as some kind of tag...
November 18, 2024 at 06:53
I didn't "cherry pick" anything. And I didn't "misrepresent" anything. YOU picked out a quote by him, and cited ME in connection with that quote by hi...
November 18, 2024 at 06:49
Oh, for Pete's sake. I just wrote that I am not, at least at this time, interested in sorting out the disagreement between you and him. Rather, at tha...
November 18, 2024 at 06:39
No, YOU quoted a certain argument by him and followed with a comment about me, as if that argument is not compatible with what I said. So I made clear...
November 18, 2024 at 06:28
There are a lot of things to untangle in a discussion. I didn't purport to vindicate everything the poster has said. And I am not, at least at the pre...
November 18, 2024 at 06:21
You said It's not an interpretation of the definition (as if I intepret it to be the definition of as if I interpret the defintion in some strange way...
November 18, 2024 at 06:17
READ exactly what I wrote: I referred exactly to this: "The argument is valid; the conclusion follows from the premise. We can show this in four parts...
November 18, 2024 at 06:14
(1) You don't know that. (2) Even if it were true, it doesn't prove much. (3) I wrote again in my first post today that I am not arguing what the defi...
November 18, 2024 at 06:11
It's not a definition of validty! It's not supposed to be definition of validity! You are terribly confused and not paying attention to what I've said...
November 18, 2024 at 06:06