## I want to know where there is the flaw in my argument

I came across following problem to finding whether the following language is decidable or semi-decidable or not even a semi-decidable.

$$L: \{\langle M\rangle: M\space is\space a\space TM\space and\space |L(M)| \ge3\}$$

Now thinking intuitively I conjectured that this language is semi-decidable. We can say yes when the input does belong to $$L$$. But, we can not say no when the input does not belong to $$L$$.

Now, I formulated following reduction from complement of halting problem $$\overline{HP}$$ which is not semi-decidable (non $$RE$$).

$$\overline{HP}: \{\langle M, w\rangle : M\space is\space TM\space and\space it\space does\space not\space halt\space on\space string\space w.\}$$

$$\tau(\langle M,x\rangle) = \langle M’\rangle$$.

$$M’$$ on input $$w$$ works as follows. It erases w, puts $$M$$ and $$x$$ on its tape, and runs $$M$$ on $$x$$ and accepts if $$M$$ doesn’t halt on x. Otherwise it rejects.

Proof of validity of reduction:

$$\langle M,x\rangle \in \overline{HP} \implies M\space does\space not\space halt\space on\space x \implies M’\space accepts\space all\space inputs\space \implies|L(M’)| \ge 3\implies M’ \in L$$

$$\langle M,x\rangle \notin \overline{HP} \implies M\space does\space halt\space on\space x \implies M’\space rejects\space all\space inputs\space \implies|L(M’)| < 3\implies M’ \notin L$$

According to above reduction $$\overline{HP}$$ should be recursively enumerable$$(RE)$$ which it is not. So, $$L$$ should not be $$RE$$ but it indeed is $$RE$$. So, my reduction must be flawed.

Please point out where I messed up.

## Language independent protocols describing argument passing and parsing?

Scenario

I wrote a powershell installation script that passes a line of arguments to a .jar file through the command line. It comes down to:

1. Converting an object into a list of strings
2. Concatenating them into a single single string:
3. Executing the java -jar .jar
4. Parsing the back into an object inside Java.

Several design choices I face are:

• When I update the list of features, I will have changed the number of options the java parser should convert into the features property of the installation object. It might be wise to pass an explicit argument that contains the number of features, so that, in the future the script will immediately throw an error, if for some reason I/someone has forgotten to update the number of features that the argument parser should facilitate.
• It feels like a work around of implementing a proper integration. It might be better to store the object as a temporary configurations.txt file that is read explicitly by the custom java parser.
• Do I prepend every argument value with an -<argument name> or just hardCode the argument order into the argument order in both in the .ps1 script, as well as in the .jar script.

Since this is such a wide range of questions, I was wondering whether:

Question

What are the language-independent argument passing protocols?

## What is the use of [_secure => true] in controller redirect path argument in Magento 2

Anyone can explain to me what is the use of [_secure => true] in controller redirect path arguments in Magento 2.

## Magento 2 – Passing argument from backoffice in Category Layout Update XML field to frontend module or phtml

In Magento 1 I sometimes used this way to pass an argument to a category, directly from the back office

<reference name="product_list">     <action method="setData"><key>giftCardId</key><value>955</value></action> </reference> 

Could you tell me what will be the equivalent syntax in Magento 2, Using the same way:

Category > Design > Layout Update XML

The main idea is to pass a value for a specific category, that could be retrieved in a custom module in frontend.

Edit: I know that I can add a custom category attribute to do that too, but the point is really, does an equivalent syntax exists.

## ZAP Proxy unable to launch browser invalid argument: can’t kill an exited process

• Using OWSAP ZAP 2.8.0
• On Ubuntu 19.04
• With openjdk version 11.0.3 installed

When clicking the “Launch Browser” button on ZAP to launch the HUD enabled browser for ZAP no browser is launched and an error is printed in the terminal (full output below).

I have already tried Chromium and Firefox, both have the same issue.

Another issue I’ve been experiencing, although potentially unrelated, is that when trying to use ZAP in Firefox I am unable to visit HTTPS sites due to the certificate not working correctly (even though it’s installed on Firefox).

I have also tried launching it with sudo zaproxy (as apposed to just zaproxy)

While writing this I restarted ZAP and now the “Enable HUD” checkbox unchecked and is disabled (greyed out), clicking “Launch Browser” does nothing and prints the same error.