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TheRumpledOne
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peter_77_peter wrote:well for the record, I´ve studied mathematics at the university, having courses in logic as well as in probability. Logically you´re completely right TRO, but, as jthumbling set up a connection to probability which was probably the way Michal was thinking to, your statement gets some probability, therefore, of course you´re right, Michals Statement can be proven to be no logical tautology, but, assuming that Michal simply lacked saying that his statement has been made within a framework containing the perspective of probability, as I`ve tried to explain, jthumblins statement saying that the both of you are right, can be clarified explaining the integration of your logical point of view into a framework based on probability....of course your point of view gets some extra points for trading relevance, because probability deals with assumptions and large numbers, that are kind of impractical for real life, but still, this framework can help clearing up the mind if you are dealing with risk more generally.

maybe I should change my forum name to mad scientist.....lol.....

Thank you, Peter.

Now, can we get back to TRADING AND MAKING MONEY rather than LOGIC DEBATES!

TheRumpledOne
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"I'm Pamela Anderson and Pamela Anderson has blonde hair, so I have blonde hair", I have just said a tautology which is true regardless of whether I really am Pamela or not."

If "I'm Pamela Anderson" is FALSE, then the tautology is FALSE!!

X
X <-> Y
then Y

only when X is TRUE!!

michal.kreslik
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TheRumpledOne wrote:"I'm Pamela Anderson and Pamela Anderson has blonde hair, so I have blonde hair", I have just said a tautology which is true regardless of whether I really am Pamela or not."

If "I'm Pamela Anderson" is FALSE, then the tautology is FALSE!!

Tautology can't be false. Tautology is always true by definition: "In propositional logic, a tautology is a statement which is true regardless of the truth value of the substatements of which it is composed."

Have a look at the link you sent me earlier:
http://planetmath.org/encyclopedia/Tautology.html

They feature this example of a tautology:

"It is a sunny day and on a sunny day the rain does not fall so the rain does not fall."

My example was:
"I'm Pamela Anderson and Pamela Anderson has blonde hair, so I have blonde hair."

So my example is a tautology:

I'm Pamela Andreson (It is a sunny day) and Pamela Anderson has blonde hair (and on a sunny day the rain does not fall) so I have blonde hair (so the rain does not fall).

So my example is a tautology which is true all the time, regardless of me being Pamela or not

Anyway, now I really think that we should get back to making pips. This is not making us any

Michal

TheRumpledOne
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Michal:

"To test a statement or form to see if it is a tautology, one may construct a truth table. If it turns out that one obtains T in every column, then the statement is a tautology."

http://planetmath.org/encyclopedia/TruthTable.html

( P ^ ( P -> Q)) -> Q

P = Pamela Anderson

Q = Has blonde hair.

In this case P is true and Q is true.

P = Jaclyn Smith

Q = Has blonde hair

Is it still true? The form is valid but you don't get TRUE!

Because, in reality, Q is FALSE. So P -> Q evaluates to T -> F which is ALWAYS FALSE!

Since Michal is NOT Pamela... ( the rest should be obvious to the reader )

QED

eudamonia
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Well I don't know about any of this logical semantics mumbo-jumbo, but I do know a couple of things:

1) Michal ain't Pamela Anderson. Just sounds like plain common sense to me. I don't need no fancy tautology to figure that out.

2) If my stoploss is 1 pip the odds are real good that it's gonna be a losing trade, whereas if my stop is 2000 pips the odds are real good my stop won't be hit. I really don't see how there can be much arguement about this. If anyone wants to argue this point then please show me your account statement with 50 trades at a 1 pip stoploss and a high (ie. > 70%) win ratio is. Nuff said.

Whether any trade ends up being a winner is based on A) entry/exit logic, B) a fixed stoploss. Obviously when B becomes smaller A must be better and better to achieve the same win ratio. At a certain point I must either be able to predict the market better than Nostradamus or my win ratio will naturally decrease. Of course my expectancy may go up with tighter stops (to a point) but is another discussion.

Edward

P.S. I'm afraid I don't really see the arguement in this discussion. Just sounds like an arguement of "words". My personal feeling is that if you can't explain a concept in plain english (or another language) that 6th grader can understand then you don't really understand it yourself. It doesn't matter if it's rocket science, trading, or brain surgery.
Eudaimonia (pron.: you-die-moan-e-a) (Greek: εὐδαιμονία) is a classical Greek word commonly translated as 'happiness'. The less subjective "human flourishing" is often preferred as a translation.

Patch
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Michal & TRO

You are both right ,,, depending on ... the market, time frame, price movement, stop loss, and I don't want to add another dimension, but if we keep the stop loss at a set level and increase or decrease the profit target -- the number of winning and loosing trades may be affected ... depending on range. Is there any way to control range? This has been a very interesting discussion. I go back to something TRO said about anything can happen when the market is open, and back testing isn't worth a fake nickel. I've also seen first hand the truth of this studying the Trillion Dollar Strategy while the market is open.

All I can say is that I am thankful that I am not Pam A.
nope !
BUT
I am a FX Pirate

Jeff in Va

TheRumpledOne
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Ed:

My first post in the thread uses PLAIN ENGLISH.

michal.kreslik
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TheRumpledOne wrote:"To test a statement or form to see if it is a tautology, one may construct a truth table. If it turns out that one obtains T in every column, then the statement is a tautology."

http://planetmath.org/encyclopedia/TruthTable.html

I agree. Let's construct the truth table then.

Let's use the standard truth table for implications (for added authenticity, screenshot taken from here: http://planetmath.org/encyclopedia/VacuouslyTrue.html):

In the statement (P ^ ( P -> Q)) -> Q, there are 2 variables (P, Q), so there are a total of 2 to the power of 2 possible logical combinations. So the resulting truth table for (P ^ ( P -> Q)) -> Q will be:

( P ^ ( P -> Q)) -> Q

P = Pamela Anderson

Q = Has blonde hair.

In this case P is true and Q is true.

P = Jaclyn Smith

Q = Has blonde hair

Is it still true? The form is valid but you don't get TRUE!

Because, in reality, Q is FALSE. So P -> Q evaluates to T -> F which is ALWAYS FALSE!

What can I say - as shown above, (P ^ ( P -> Q)) -> Q evaluates to true in all possible cases. That's why it is a tautology - it doesn't matter what is the logical value of P or Q, the entire statement always evaluates to true.

TheRumpledOne wrote:Since Michal is NOT Pamela...
I hope so

Anyway, folks, since I don't really want to spend any more time on this dumb Pamela subject, I'm going to give \$100 to anyone who disproves this statement of mine:

(P ^ ( P -> Q)) -> Q evaluates to true in all possible cases, so it is a tautology.

Disproving is meant as a verifiable affirmation of some university professor of mathematics or similar subject. If any guy takes the bet and the professor proves I was wrong, I'm gonna pay \$100 to that guy and of course, I'll be happy to admit I was wrong here. If the opposite is true and the professor affirms I was right, I'm gonna take that guy's \$100. (Of course, you can ask the professor and he might tell you I am right and I'll never find out you did )

So, folks, I'm not going to react to any further aimless chatter here. I say I'm right and if someone says I'm not, then take the bet and we'll see

Michal

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"I'm Pamela Anderson and Pamela Anderson has blonde hair, so I have blonde hair."

Yes, that is a TAUTOLOGY....

However, "What we have here is FAILURE TO COMMUNICATE".

You are NOT Pamela.

Therefore, you saying "I am Pamela Anderson" is false because you are not thus making this ABSURD!

A contradiction occurs when the statements P and -P are shown to be true simultaneously. This concept appears most often in proofs by contradiction, which is proving a statement by supposing its negation is true and logically deducing an absurd statement. That is, in attempting to prove , one may assume and attempt to obtain a statement of the form , where is a statement that is assumed or known to be true.

TheRumpledOne
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Furthermore:

P = change the stop loss

Q = number of winning trades changes

Then

( P ^ ( P -> Q ) ) -> Q

is TRUE.

But:

P = change the stop loss

Q = number of winning trades do not change

Then

( P ^ ( P -> Q ) ) -> Q

is ALSO TRUE.

Finally:

Furthermore:

P = Pamela Anderson

Q = number of winning trades changes

Then

( P ^ ( P -> Q ) ) -> Q

is true too!!

What does this prove?