Please help me to understand this problem !!

Question

I found a problem on a website. But I can't understand the problem.
This problem was asked by Jane Street.
""
cons(a, b) constructs a pair, and car(pair) and cdr(pair) returns the first and last element of that pair. For example, car(cons(3, 4)) returns 3, and cdr(cons(3, 4)) returns 4.
Given this implementation of cons:
def cons(a, b):
def pair(f):
return f(a, b)
return pair
Implement car and cdr.
""

.
please tell me what I have to do? What does it want me to do?

Answer 1

def car(pair):
def return_first(a, b):
return a
return pair(return_first)

def cdr(pair):
def return_last(a, b):
return b
return pair(return_last)

Answer 2

The problem asks you to write car(pair) and cdr(pair) functions as they described them.

Answer 3

Sir will you please explain what the problem asking me to do please ...
I dont understand the question...
Thanks .....

Answer 4

goggle "closures" aka nested function.
def cons(a, b):
def pair(f):
return f(a, b)
return pair

car = cons(3, 4)
cdr = cons(3, 4)
print(car(min))
print(cdr(max))

Answer 5

Check this, I think it will help you to understand.

https://en.wikipedia.org/wiki/CAR_and_CDR

Answer 6

Thanks sir for your valuable comments .....