Logic100 - How the Usergroup unfolds in interest...

[Aetixintro]

The recommended reading to come here about plus some questions asked from interested people.

Shoot out! Just make write in the questions in here. To being with I'll take on most.

Welcome!


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(Edit:) Anybody who bothers to make this a "sticky" under/with Logic101?

[Aetixintro]

Now that Logic100 is here "I reiterate a bit":

Description:
This is the group for people who are interested in logics and who want to know more of it! We start with the 1st order logic, move up with Predicate logic, Modal logic and Quantified logic. The first book to read: The Logic Book by M. Bergmann et al. (McGraw-Hill Higher Education, any edition, 3rd, 4th, 5th).

The recommended reading for now:
The Logic Book by M. Bergmann et al., highly recommended to all people here, religious people...

+ others:
W. Goldfarb, Deductive Logic, Hackett, 2003.
R. Jeffrey, Formal Logic, Its Scope and Its Limits, 3rd ed., McGraw-Hill (Higher Educ.), 1991.
G. E. Hughes, M. J. Cresswell, A New Introduction to Modal Logic, Routledge, 1996. (Not entirely recommended, but possible choice, watch up for "frame logics".)
----
some Gödel logics, for both background, being a fellow religious person, but also for the Incompleteness notions:
P. Smith, An Introduction to Gödel's Theorems, Cambridge Univ. Press, 2007, 4th printing (apart from the editions).

Background of mine, heavier than you think, special circumstances of North Europe:
Connected earlier on 100 points, but not... that they are listening, that the Logician considered, with LPOV from Quine to go...

[Divine Insight]

Are you starting a usergroup or a course on logic?

I looked up the book you suggested and it appears to be $128.00 on Amazon. Does everyone who joins this usergroup need to purchase that book?

Why don't you look up free youtube videos and simply discuss their content?

Here's a nice one to start off with:

[youtube][/youtube]

[Divine Insight]

This is a good one too. This is the second video by the same professor. Just look at his youtube channel and you can get a lot more like these.

[youtube][/youtube]

[Aetixintro]

Dear Divine Insight

There is absolutely no-one requesting you to buy any book! The book is purely optional.

However, the book for 125 $ can provide you with much good logics and great fun after the learning too. For you to decide.

Thanks for the interest in this discussion thread. Also, this discussion thread "is meant to play along with the usergroup, providing a secondary reference until I've made a donation for a subforum or other. Let's see!

Best wishes,
Aeti-

PS: With Scientology too, I am absolutely not requiring anybody to buy books or other (above their possibility or direct/genuine interest!

[Aetixintro]

To Logics
A bit of fun with logics under the usergroup of Logic101.

The worded outline to accustom the formalisation below:
All humans are green. Some aliens, who may otherwise be normally skin coloured (brown, white, yellow...) are also green. And we get, as conclusion, the incredible that some aliens are humans (who are green). As this is incredible it is a fantasy! This is all ridiculous! In ending, we start with "all humans" so to avoid "injection" and "discharge" into the mix of logical deduction.

Demonstration of a formal logics set-up.

The deductions from above can be expressed this way, that may be more precise, but for the purpose of common language, then we leave it. Here is still:
UoD: Everything.
Humans: H
Aliens: A
Green: G (actually all green things)

Not really part:
(ForAll)H → (ForAll)G ( using the conditional → when we are combining properties leaves me the room to use the biconditional instead ≡ )
(ForAll)H ≡ (ForAll)G
(Exist)A ≡ (Forall)H
(Exist)A ≡ (Forall)G

1 │ ∀H
2 │ ∀H ≡ ∀G
3 │ ∃A ≡ ∀G
0 │------
( logical deduction in here. 2 biconditional eliminations and one biconditional introduction that ends up on the conclusion line. )
0 │-----
4 │ ∃A ≡ ∀H (should really be the biconditional introduction, but we don't go there today, it says line 4, but reality when all formalities are in, it's should be a bit lower, allowing room for the numbers inside the deduction section of this logical argument)

This is an example of a valid logical argument, but where logics is misused to make aliens appear both green and human which should be impossible in reality when human are certainly not green by natural skin colour, but rather brown, yellow, white or other...

Urls for logics, 4,
http://en.wikipedia.org/wiki/Domain_of_discourse
http://en.wikipedia.org/wiki/Logical_system
http://en.wikipedia.org/wiki/Argument_( ... _arguments
http://en.wikipedia.org/wiki/Symbolic_l ... rder_logic.

While writing under Logic100, that is intended to play with the usergroup of Logic101, I also include the suggestion for Logic102 here right away:

Suggestion is given to anybody for setting up Logic102 with
Graham Priest and Contradiction Logics placed soundly with the Austin Speech Acts and the Liars Paradox also solved.

So with this, for the people who have passed (into) Logic101, we discuss all the rest, the most advanced/"advanced", all matters logical. Also the worries under God, the Bible and the insults from "academics" against good people's intuitions for the way FORWARD!

We can set up this "chair" of reliability to serve under God and Truth, with the words over the Washington Monument,

By God and Truth, Ethics, Science, Logics and Religion - with the ecumenical Holy Books, complying with the uttermost tip point of intelligence.

Enjoy!

[Aetixintro]

Some links to start with under Logic100, from Wikipedia and SEP, by Stanford Univ.:

http://en.wikipedia.org/wiki/Modal_logic

http://plato.stanford.edu/entries/logic-modal/

http://en.wikipedia.org/wiki/Naming_and_Necessity

http://en.wikipedia.org/wiki/From_a_Log ... nt_of_View

http://en.wikipedia.org/wiki/Sentential_logic

http://en.wikipedia.org/wiki/Predicate_logic

http://en.wikipedia.org/wiki/Quantification

http://www.cc.utah.edu/~nahaj/logic/str ... index.html - not Wikip. or SEP

This should suffice for our 1st Order Logics this far. I also suggest that we drop "Higher Order Logics" because it may not provide "value" into logics investigations, to my knowledge, Liar's Paradox discussion included.

[Aetixintro]

Under Logic100 - Logic101 - Logic102, The Liar's Paradox solved! Here:

Generally the liar paradox is shown to be meaningless (now).

Liar's Paradox: I consider the Liar's paradox to be meaningless. If one ends up in a Liar's paradox in the first place, I suggest there's something wrong with the descriptions or explanations. So you should improve on these before one give's up on the situation and ends in Liar's paradox. It's also puzzling to me how Liar's paradox enters Godel's Incompleteness argument. I'll look more into Godel's Incompletenss, but this is not important to this writing. My opinion on Liar's paradox stands!

2nd, still against the Paradox, "For people who think that to make a title "This is not a title" on a book (Raymond Smullyan, fx.) matters, you do not do much other than positing a Austin statement, that is, you commit a speech act, NOT logics!"
Further, "To say that the total of field isn't provable, isn't good enough, because the field always remain contestable (until one can begin to look on the results consider what "in the World" that can possibly remain in the field to discover!"

Besides, DON'T LET THEM LIE TO YOU and without the academic excuse to do so too!

[Aetixintro]

The Logical Operations, in making the logical deductions, by fx. the inside of the binding of The Logic Book:
Reiteration
P
P

Conjunction Introduction,
p
Q
P & Q

Conjuction Eliminnation,
P & Q or P & Q
P or Q

Conditional Introduction, see Wikip.
Conditional Elimination, see Wikip.
Negation Introduction, see Wikip., quite "complex" in terms of 1st order logics.
Negation Elimination, see Wikip., same.
Disjunction Introduction, see Wikip.
Disjunction Elimination, see Wikip., same as with the Negation.
Biconditional Introduction, see Wikip.
Biconditional Elimination, see Wikip.
Modus Tollens (MT), see Wikip. One of two logical operations in science, the other being Modus Ponens (MP), by Conditional Elimination!
Disjunctive Syllogism (DS), see Wikip.

13 Logical Operations accounted for, though not entirely visualised!

Lastly, remember the difference of a premise that looks like this:
God
G

and a premise that looks like this:
Necessary Ethics, by 10 Commandments, imply necessary God
□E → □G

.

[Aetixintro]

Another one to include, the Hypothetical Syllogism, no. 14. Plus some "time logics", in the legal sense, important to Human Being of Law by securing legal reasoning and securing procedures.

Thus we have, Hypothetical Syllogism (HS):
C ⊃ E
E ⊃ T
C ⊃ T as conclusion.

Philosophy of Law: Legal Reasoning Closure Principle Philosopher, legal reasoning, being valid, has to comply with logical entailment and that this is minimally the claim that it does, apart from the (many book) examples that it does. (This is only a formal note, not the text for lawyers to actually having to sit and make these logical texts themselves, i.e., to burden them with much extra work.)

The Closure Principle in essence consists only of these Hypothetical Syllogisms, be it the legal matters (now) or the world of chemical reactions under Epistemology.

In addition, time in logics can be solved like this:

Predicate logic,

UoD
20:20 PM, 2013-09-09: Km (person m is suspected to have committed a murder)
20:20 [...]: Lm (person m after the time of murder)
20:20 [...]: Bm (person m before the time of the murder)
so on...

Sentential logic,

UoD
20:20 PM, 2013-09-09: K (person m is suspected to have committed a murder)
20:20 [...]: L (person m after the time of murder)
20:20 [...]: B (person m before the time of the murder)
so on...

(Again, predicate logic is a bit more powerful...)

Additionally, you can check up various time-logics yourself, sentential, predicate, modal...

The Human Being of Law
- Formalism (strongest - note) has formerly "won" the Human Rights, UDHR and ECHR alike, also to service globally! Please, see reference with the UN.