foundations | Functional Programming in Scala | Functional Programming library

I can't seem to figure out why I keep getting 1st and 3rd row. I am skipping 2nd for some reason. Here's my code

I'm trying to examine how the type checker works on the following function, but can't understand how the type checker works in the second (the nested) match clause:

I'm new to Coq and try to learn it through Software foundations. In the chapter "Logic in Coq", there is an exercise not_exists_dist which I completed (by guessing) but not understand:

I am used to Racket and I am trying to learn Common Lisp. In Racket, symbols evaluate to itself as showns by Dr Racket's REPL:

How can I automate my scoring formula to count odd rows as 1 for TRUE and even rows as 1 for FALSE?

I'm trying to import a quiz that I found in the back of an ancient, eldritch tome into G Sheets. The order of the questions is fixed - the notes in the margins are very specific that a "dire fate" awaits anyone who "dares disturb these ancient mysteries." So I'm putting the questions in G Sheets in order, but in order to count the scores, I need to have every odd row give +1 if the answer is TRUE and every even row give +1 if the answer is FALSE.

I know I could brute force this with addition, such as

=COUNTIF(C2,TRUE)+COUNTIF(C4,TRUE)+COUNTIF(C6,TRUE)...

but every minute I spend typing, I feel the tendrils of existential dread gnawing at the foundations of my soul. Plus, that sounds super-boring.

So, is there a way to automate having COUNTIF() (or COUNTIFS()) do this for me?

• ROW(), but it doesn't seem to play nice with COUNTIFS(), just gives me a 0.

=COUNTIFS(C2:C666,TRUE,A2:A666,ISEVEN(ROW)

• Adding a cheater-column that does this for me with ROW(), but I'm worried that tinkering with the table will unleash untold horrors on our world.
• Maybe something with DCOUNT or ARRAYFORMULA? But those seem to me MORE forbidden than the Necronomicon, not less.

Did try this, but it's just giving me the total number of true values:

=ARRAYFORMULA(COUNTIFS(A3:A24,ISEVEN(ROW()),A3:A24,TRUE))

What else y'all got?

I was reading a blog post about the use of sigma-algebras in probability. The author gave a simple example, followed by some Python code showing how he would solve the problem in Python. However, when I tested out his Python code using Google Colab, I ended up with error messages when I ran it (TypeError: 'function' object is not iterable).

I'm not much of a Python user, so I've never used it to solve mathematical problems, but I was reading the blog post as I would like to learn how to use it to solve data science problems like this. I searched Google and couldn't find any other articles about using Python to solve sigma-algebra, so I thought I'd post the question in case other people had tried to run the code to learn Python and found the same errors. I was taught Matlab and R at university, not Python.

Here is the URL of the blog post: https://towardsdatascience.com/foundations-of-probability-7a792e7eea5

Here is the code he supplies:

(the exercise is from Software foundations, I can give all relevant definitions but there'll be a lot of them) Consider this:

I followed setting-up-git guide. It didn't work. I also tried to follow the GitHub's connecting-to-github-with-ssh guide. It didn't work either. I keep getting same error :

host key verification failed.

After googling found this suggestion: ssh-keygen -R hostname.

Tried replacing hostname with github.com and 13.234.176.102.

Still same result : do_known_hosts: hostkeys_foreach failed: No such file or directory.

The .ssh diirectory cotains below files:

2

I'm going through software foundations and ran into an error. (https://softwarefoundations.cis.upenn.edu/lf-current/Maps.html)