Context Free Grammar - Production Rule validation - grammar

I need help about this problem.
Given the following production rules, which ones are not valid in CFG:
A -> aaVAa
aAs -> Vaa
SS -> a
S -> ɛ
S -> S
Please help me, I need to explain if its valid or not. Thank you so much guys!

The second and the third productions. A production only can be performed on a single non terminal symbol.

Related

Questions related to splunk builtin macros in correlation search

I am not sure if this is the appropriate forum to ask this question, but really need help and I am stuck. So here goes : I am exploring splunk enterprise security and was specifically looking into analytic stories and correlation searches.
For example :
Analytic story : Trickbot
Correlation search : Attempt to stop security service
| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name = net.exe OR Processes.process_name = sc.exe) Processes.process="* stop *" by Processes.dest Processes.user Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
|lookup security_services_lookup service as process OUTPUTNEW category, description
| search category=security
| `attempt_to_stop_security_service_filter`
I am trying to understand what exactly this code is doing, but stuck at these macros like security_content_summariesonly, drop_dm_object_name, security_content_ctime, attempt_to_stop_security_service_filter. I can't find definitions for these macros anywhere. I have tried to look into -> settings -> advance search -> macros, but these are not listed there.
Can somebody help ?
If you have access to the host(s) Splunk's running on, you can find the definitions in $SPLUNK_HOME$/etc/*/macros.conf
If you don't have that access, then it's possible you don't have permissions to see the definitions of those macros
However, you can always use the Job Inspector to see how Splunk translates what you type into what it runs
If you have the query in a search window then click on the query and type Shift-CTRL-E to have Splunk expand all of the macros for you.
I can tell you the drop_dm_object_name macro is just rename $1.* as *. The other macros are specific to their app.

Could you please provide an example of DispatcherOneToMany?

I want to connect multiple WebRtcEndPoints to one filter, so I want to use DispatcherOneToMany with multiple HubPorts.
I build the pipeline like this:
PlayerEndpoint -> Customized GStreamer Filter -> HubPort –> DispatcherOneToMany -> HubPort -> WebRtcEndpoint
But it doesn't work, I can only see the video in the first browser connected to the WebRtcEndPoint.
I will appreciate it if someone can provide a demo.
Thank you very much!

How to comment script in Datamapper Mule

I have a XML to XML mapping in DataMapper. Obviously soon after mapping done script will be present. How to I comment any line in script( Example here output.status line).
I have tried like this // but not seems to be commented.But could see by default Mule commented //MEL.
//MEL
//START -> DO NOT REMOVE
output.__id = input.__id;
//END -> DO NOT REMOVE
output.vendorReference = input.Ref;
output.status = input.overallStatus;
We know can remove the mapping or delete in script. But is there a any way we can comment it. Please suggest. Thanks in advance.
I could not understand why you want to comment the output status line.
Generally the scripting will allow // for commenting. In case of any filtering to be done then there are many features supported by MULE. Can you please elaborate your requirement so that we can help better.
http://blogs.mulesoft.com/7-things-you-didn%E2%80%99t-know-about-datamapper/
https://developer.mulesoft.com/docs/display/current/Datamapper+User+Guide+and+Reference#DatamapperUserGuideandReference-Examples

VB.NET Console and RichTextBox difficulties

I am new here. I am very happy that I joined this website, because everyone here is so smart!
Now, let's cut to the chase! Hopefully, I will be able to explain everything properly.
I am creating a Visual Basic application. It's supposed to reassemble a so-called "fake programming language." It's having some issues though.
Let me show you an example before explaining:
If RichTextBox1.Text.Contains("console output >'insert comment';") then
Console.WriteLine("insert comment")
End If
Now, what I want here is a custom input. (if someone types "I want cookies" then I want the console to say that!
For instance, if I type:
If RichTextBox1.Text.Contains("console output >'Insert something here';") then
Console.WriteLine("Whatever the user wrote!")
End If
I just want to possibility to write whatever I want, that's all! I hope I made myself clear, because I am having a hard time explaining here. Help is appreciated! Thank you!
You need to match just the part with the console output > and then replace that portion of the string with empty space, like this:
If RichTextBox1.Text.Contains("console output >") Then
Console.WriteLine(Replace(RichTextBox1.Text, "console output >", ""));
End If

how to enable neocomplcache quick match?

I don't know how to enable quick match in the neocomplcache vim plugin. I put
let g:neocomplcache_enable_quick_match = 1
in my .vimrc, but it's useless. When I press - nothing happens.
According to the help file, there is no quick fix feature anymore. You need to use unite for that:
A: Quick match feature had been removed in latest neocomplcache
because quick match turned into hard to implement.
But you can use |unite.vim| instead to use quick match.
imap <expr> - pumvisible() ?
\ "\<Plug>(neocomplcache_start_unite_quick_match)" : '-'