Help please! Can someone help me understand this code?

Question

x = 5
def fun(x):
x = x - (x-2)
return x
print(fun(fun(fun(x-1))))

Answer 1

Inner function( fun(x-1) )is called first which returns 2 . value 2 becomes argument for another inner function (fun(2)) and this is how it goes on ..

Answer 2

You should start with the innermost function
fun(x-1) and put for x 5. That mesns fun(5-1) = fun(4). So from definition of the function:
x= 4 - (4 - 2) = 4 - 2 = 2
So this return 2.
When you put this 2 into next function fun you get:
fun(2) = 2 - (2 - 2) = 2 and so on, and so on.
For this reason the result is 2.

Answer 3

What is pcep?