## What are some ways to formally express something as ‘few and not fully mature’?

I am trying to make a point of certain research areas are still in its young stage and is not ready to be widely used. What are some better way to express this?

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## How do I formally test outliers from a linear regression?

Hello (and thanks for reading this).

I have a set of data that looks at the area of remaining retina against age. I have three points of data per patient. We know that over time, the area of remaining retina decreases exponentially. I have done a linear regression to model loss of area over time (see graph). X axis = age, Y axis = retinal area (log scale).

In this data there are some patients that are outliers because of their genetic mutation. I am interested in doing a formal test to see whether because of this mutation, they have a significantly larger area of retina remaining for their age, compared to the rest of the cohort. I have read about various tests (Grubbs, Dixon etc) but they don’t seem to apply here for bivariate data. I am aware that I can identify outliers by visualising them, but I want a formal test with a p value if possible to satisfy reviewers who have requested it.

Please see the attached graph to demonstrate what the data looks like. The red and green dots are the patients I am interested in testing. Any suggestions on how to analyse this would be most appreciated. I am using Prism 7 for analysis. I can’t seem to find an answer for this question on stack anywhere. As you can probably tell, my stats experience is fairly limited. Thanks for your help.

Age vs Area of retina (mm2)

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## Can an argument be formally valid with sound premises and still be informally fallacious?

Consider the following two assumptions:

1. Validity Assumption: Assume an argument is valid. It follows all the formal logical rules of inference. The inference contains no formal logical fallacy.
2. Soundness Assumption: Assume the premises of the argument are sound, verified by a competent subject-matter expert.

Given the soundness assumption, the validity assumption would imply that the conclusion is logically true.

Is it possible for this argument to still be an example of an informal fallacy?

What makes me think this is possible is that establishing the soundness assumption, which I assumed to be true, cannot be done with absolute certainty. The subject-matter expert verifying the premises as true may have made an error of judgment. The validity assumption is more reliable as an assumption than the assumption of soundness since it can be checked with a computer without involving human judgment.

This would make the list of informal logical fallacies valuable. They would be ways to test sound and valid arguments by identifying places where the argument could go wrong.

What I am looking for are examples of such situations that would answer the question in the title as “yes” or an argument that such examples are not possible.

To repeat the question: Can an argument be formally valid with sound premises and still be informally fallacious?

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## Using functions in formally well defined statements

Given a function \$AnyS(n)\$ that returns an undefined number of sets with \$n\$ different aleatory integers, and the function \$Min(S)\$ that returns the minimun integer of a set of integers, and the function \$Avg(S)\$ that retuns the most close member of a set of integers to the average of its members.

Is this statement formally well defined? Must be functions declared before?

\$\$forall R in (forall S in AnyS(9)) implies Min(R) neq Avg(R)\$\$

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## Formally prove that \$lim(frac{2n}{n+1})=2\$

Taking Real Analysis for the first time and having trouble grasping what i need to show for the proof. I know i need for any \$epsilon > 0\$, there exists a positive integer \$N\$, such that if \$n geq N\$, then \$\$biggl|frac{2n}{n+1}-2biggr|= frac{2n}{n+1} < epsilon \$\$

I’m not sure where to go from here. Do I need to solve for \$n\$ on the right hand side?

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## How would formally ask someone to confirm return date to book a ticket

I would like to book a return ticket back to my hometown for a particular date. I need to ask my someone before finalizing the date. How can I express that in a question form? I have few examples:

• (For) which date/day should I book my return ticket?
• When should I return?
• I am thinking of returning on xyz date. Is that okay?
• Which date/day should I return (on)?

Similarly, is the following sentence grammatically correct?

• I booked my return ticket for my hometown for xyz date.

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## Question: “Unwritten” rules of baseball…If they’re not in the books or something that’s formally enforced why take them seriously or follow them?

Question: “Unwritten” rules of baseball…If they’re not in the books or something that’s formally enforced why take them seriously or follow them?

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